Foretravel Owners' Forum

Well, I'm sorry to have to post this, but it must be done.  We had extensive brake work done on all 4 corners at MOT the last couple days.  We left NAC headed home this morning.  Got to Palestine, and noticed a "hot brake" smell, but assumed it was due to new pads all the way around. Wrong.  Got about 10 miles NW of Palestine on HWY 287, and saw smoke coming from right front corner, along with STRONG smell.  Pulled over on side of road.  RF wheel was VERY hot, but no flames.  Smoke cleared immediately soon as we parked, and wheel is slowly cooling off.  I looked at sight glass on hub, and oil level is good.  I think the problem is brake pads dragging.

On that corner, MOT replaced the axel seal, replaced both brake pads, installed new slide pins and helper springs, greased the brake with correct grease, and adjusted slack adjuster.  Somewhere in that list, something went wrong.

Question:  Is there some simple way I can make a "roadside" adjustment to the brake to make it stop dragging?  We want to come back to NAC to get this corrected, but obviously can't drive far in this condition.  I'm afraid I have zero experience working on these brakes, but I have plenty of tools and can follow instructions, if anyone can tell me what I need to do.

We'll worry about who did what wrong later - no need to discuss that now.  Just looking for technical assistance.

Thanks in advance!    Cell:  432-two-one-five-93three5

Had similar issue after service at TN RV. In my case it was a bad slack adjustor.
With retarder off, step hard on Brake  at a slow speed. I was able to get mine to release enough to drive. Mine was intermittent, usually an issue in first 50 miles after cool down.
Pads and rotor will be toast, probably more on that corner

Thanks, Tim.  I'll try it.

Also you can try to back up to release the pad.

My guess would be that whoever did the grease on the brake didn't go through the correct purge procedure when they filled it up and it locked up. 

You could crawl underneath and manually back the slack adjuster off a bit if needed.  You'll likely need the if you aren't familiar with what to do.

Update.  A friendly truck driver stopped, and showed me how to back off the slack adjuster.  He said that should get me back to NAC.  If all goes well, I won't post again until I speak to MOT and see what they say.

Thank you for your attention, and special thanks to Mike (Pamela & Mike) for calling me, and Tim, John S and Robert for responding!

This Forum is PRICELESS!!!!!!!!!

Chuck,just make sure they check the rotor and parts in that area for heat cracks.

Suggestion for anyone having brake work done, my shop did this and recorded the temp readings on the final invoice:

Take coach on a test drive, upon return immediately read and record all 4 disk temps with an IR gun.

This will verify there are no dragging pads or sticking calipers.

Also, as mentioned, I gave the technician a copy of the Meritor manual, and reviewed the grease purge procedure with him.

Peter that is a good idea, but being the work done at MOT who must surely know the proper technique due to all the FTs they work on, this "problem" sure does not look too good for them in my books. I know "things happen" but this would be a serious one in my estimation.
JohnH

Agreed John.

My take is stuff happens to best of shops, what sets them apart is frequency of failure to fix right first time, and how is the correction handled from a customer experience viewpoint.
In the auto repair business, 3% is considered very good first fix failure rate, with about 50% of that number attributed to bad parts.
What happens next is where the rubber meets the road

When can we expect your howto on slack adjuster adjustment! :)

Let us know what MOT finds...

see ya
ken

Update.

We're back in NAC, staying at the FOT RV Park.  Slacking off the automatic adjuster did the trick - front wheel stayed cold on return leg.  I could definitely feel a pull to the left when braking, since the RF brake was out of service.  Took it easy stopping, so as not to stress the remaining three (freshly rebuilt) brakes.

I pretty much agree with everything posted above.  I will get with MOT and see how they handle this.  As said above, everybody screws up, but how they recover from the error is very important.  I will report to the Forum on their response and "fix".

I have a non-contact infrared thermometer, and you can bet I will pull over and use it, frequently, the next time we take off.  I'm going to be mucho paranoid about my brakes for quite a while after this interesting little episode.

Ken:  I actually already had plans to post a couple photos of the very simple procedure the trucker used to relieve the pressure on the brake pads.  I'll work on that tomorrow, if the weather is decent.  To whet your appetite, all the tools you need are:
1.  A set of chocks
2.  A big screwdriver
3.  A Crescent wrench

I'll post more when I know more!  8)

Chuck, we just left camp Foretravel this morning. Really sorry we missed you.

Regarding "standing behind your work" please see my latest post in Turbo Won't Boost. Bernd is a great example of standing behind a painful and expensive mistake and to do it with such grace.

I went to Sears and got a set of those wrenches that have a ratchet on each end and
have found many uses in tightening and loosening nuts, bolts, etc. on the MH, but the
handiest thing was the one that fit the slack adjuster on the brakes. First use a little
cleaner/lubricant spray to get salt corrosion and road grit off the lock/safety ring. It usually
will slide up and down freely, if not as Brett says persuade it a little. Then you can tighten
or loosen the brake. The old rule of thumb used to be to tighten down tight and then back
off two clicks of the safety lock. The main variable here can be if you have wear in the slack
adjuster. If these are loose and wobbly by all means replace ASAP. I know there are many
on here that know far more about this subject than me. Hope to hear from them.

Brast of luck on your travels,

Carter Langford
Nac-

It sounds like you are describing the old drum brake adjustment procedure. Not self adjusting discs

You are right. My coach has the drums. Please tell how it is done with the new ones,
so if I ever get into the 21st century I will know. That is why I said there were more
knowledgeable people on here.

Thanks,

Carter

I have revised the "Subject Title" of this thread to remove the "HELP - EMERGENCY" connotation.

Texas Guy:  Thanks for your phone call yesterday, and kind offer to help.  Between you and Mike Harbordt we had a great local backup team in place, in the event we had not been able to get back on the road.  You NAC dwellers must stay pretty busy bailing out Forum members!

I will post a couple photos later today showing the "trick" to backing off the auto slack adjuster.  Simple once someone shows you how.  :facepalm:

I think any shop working on brakes should  "stand in front of their work."

Carter,

I know this is drifting off subject and may need to be split out but for any layman the 1st thing you need to do is read the Meritor manual twice before you start any repair. After reading over this print out a copy so you will be able to refer to it while you are at your coach working on the brakes.  Here is a link
There are several ways to adjust your slack adjusters on disc brake adjusters that will work but I recommend getting the slack adjuster guide #2297-E-4789 (the one I have is Yellow).  This is the simplest way and as a bonus if you have the manual from above printed out it tells you the proper use of mentioned guide.

Pamela & Mike

Again the video is for drum brakes not disc. Wait for Chuck to post the disc brake release info if you have disc brakes

As promised, here is what "the friendly truck driver" did to get me back on the road.  It is exactly what Robert suggested in his post (above).

First, he asked me if I had chocks, because he said it was safer working under the coach with them installed.  Being a well prepared owner, I did, and we put them in place at the rear wheels.

Then he asked for a screw driver and a Crescent wrench, which I was also able to provide.  We both slid under the front of the coach (so I could see what he was doing).  Looking at the brake (photo #1), he pointed out the auto slack adjuster (black greasy object in center of photo #2).  He used the screw driver to lift up on the "pull pawl" (spring-loaded button in photo #3).  Doing this disengages the gear in the slack adjuster, allowing you to adjust it.  Holding up the "pull pawl" with the screw driver (I had to drop the screw driver so I could hold the wrench and my camera), he then turned the square adjuster screw in a clockwise direction with the Crescent wrench (photo #4).  Doing this rotates the upper part of the slack adjuster away from the air chamber, and releases the excess pressure on the brake pads.

THAT'S ALL THERE IS TO IT.  ^.^d

WARNING:  This procedure renders the brake inoperative, so use caution when driving, cuz you'll only have 3 brakes!

The steps for doing this procedure are all contained in the Meritor Maintenance Manual mentioned in Robert's post (above), but they are not specifically listed as a "emergency procedure".  Instead, they are scattered around in various sections.  If you knew nothing about these brakes (pretty much described me before this incident), it might take you a while to figure out this solution.  Being shown what to do makes it simple!  I owe the "friendly truck driver" a big debt of gratitude.

While waiting to get back with MOT, I have been studying the manual (link below).  I now have a pretty good understanding of how these stoppers work.  The next time I have a "brake emergency", I will be much better prepared.  8)

Great Pics !

Thanks,

Carter

Chuck, something to think about is all the extra heat that your front tire has received. Might threw that in when you talk to MOT. Would be Big safety concern to me. Could have even damaged the valve core stem seals. 

Chuck, what a nice write-up and great images to "show & tell." I'm pleased to hear your saga ended safely.

Also, nice to meet you at Ft. FOT the other day. All the best. Paul

I find a 5/16 wrench works well on the square drive if you don't have a square socket to fit it. You can buy a ratcheting tool made for these adjusters it comes with a handy dandy tool to hold the adjuster out.

Please if you don't know what you are doing be careful with this. Adjustment is easy once trained. I prefer to tighten the adjuster until it stops and then back off 3/8 of a turn and measure stroke on a 90 psi apply then I jack it up and make sure the wheel turns free.

Here is the slack adjuster tool.

http://www.tooldiscounter.com/ItemDisplay.cfm?lookup=KAS4651&source=froogle&kw=KAS4651&gclid=CjwKEAiAj7TCBRCp2Z22ue-zrj4SJACG7SBEIOyUtYEosI7RqHcC_QTrQMU2gc0ij6QnhKHOLV1KGRoCCpHw_wcB

I understand and concur with your concern, Derek.  I only posted this procedure as a emergency action to enable members with a locked up brake to get their coach off the side of the road, without resorting to calling a mechanic or a tow truck.

If this emergency procedure IS used, the coach should be driven (slowly and carefully) directly to a qualified service facility, where it should be inspected by a experienced technician to determine the cause of the malfunction.

The proper adjustment of the brake caliper and slack adjuster is clearly explained in the manual I linked above.

Is there a reason that a person would not want to degrease and wash off the dirt and grease residue in the pictures ??  ( sorry, another dumb question perhaps ).

Robert,

Again, not a dumb question.  I share your feeling that wiping off the excess grease with a rag would be desirable.  However, in my experience very few "grease monkeys" (OOPS - I mean Professional Chassis Lubrication Technicians) worry about all those globs of goop, assuming I suppose that it will eventually fall off or blow off.

When we finally get back to home base, you can be sure I will be under the coach doing a little "housekeeping".

Cleaning excess grease off is not a bad thing however going crazy with heavy cleaners and brake clean can cause issues. The release can become seized also at the end of the slack there are two pins that go through the clevis and the slack to transmit the force from the chamber. If these pins do not rotate freely when not under braking force they can cause the brakes to not release correctly and can either wear out the pins or the clevis or the slack itself.

Chuck,
I'm back on the forum again for a bit, and am sorry to hear about your problems. I hope MOT does what is right by you and am glad you were able to make it back to NAC safe and sound.
Take care and happy landings!
Len

Update:

Well, today was a mixed bag.  MOT had us come to the shop first thing - got us right in a bay.  The techs pulled the RF wheel and inspected the brakes.  The first thing they found was the bearing "play" was a bit too tight.  On that corner they had replaced the inner oil seal last Wed., so the whole spindle assembly had been apart and back together.  They also determined that the brake caliper did not have sufficient grease due to a big air bubble trapped inside (?).  So anyway, they reset the bearing clearance (used a dial indicator), greased and purged the caliper, greased the slack adjuster, adjusted the slack with the correct yellow template, and buttoned everything back up.

I went out for a long test ride with Kieth (Risch)  He drove at varied speeds, exercised the brakes, and stopped several times to check the brake rotor temps with a infrared thermometer.  He said everything felt OK to him, and the temp checks looked normal.  He did ask me if our wheels had ever been balanced, and I said no because the coach had always felt extremely smooth to me at all speeds.  Otherwise, nothing notable was found.

This work took about 3 hours, and of course there was no charge.  Since it was too late to leave for home, we decided to take the coach for a extended drive around the loop and up and down Hwy 59 north of town.  The coach felt pretty good as far as braking, but I soon became aware of a pronounced "shimmy" in the steering wheel.  This occurred between 60 and 65 mph, and seemed to "come and go".  Since the coach was dead smooth with zero steering problems before this work was done, I decided the shimmy was not a good sign.  Got back to the FOT parking lot, and called Kieth.  I told him what I felt in the steering, and he agreed it was not "right".  He said they had checked the brake rotor runout, and it did not appear to be warped, but he wanted to take another look at it.

Bottom line - we're going back to MOT (again) first thing tomorrow and let them have another look.  I'm not leaving NAC until I'm convinced everything is correct.  So far, MOT has been willing to put me ahead of other service customers, and is trying to work with me.  Hopefully, tomorrow will be our last trip over to their shop, and we can soon head for home.

Will report again tomorrow!

My guess is the rotor got warped. When you drive it and lightly touch the brake pedal it would be more pronounced. Also after getting warmed up the steering would start to pulse.

That is exactly what I felt - the "pulsing" in the steering wheel.  But I did not detect any odd feel through the brakes under light application.

On the side that got hot, I would have expected new rotor and pads. Both would be suspect after being exposed to that heat. Did they re use pads? Definitely would ask for new rotor and pad on that wheel at no charge

They did install new pads.  We'll see about the rotor tomorrow...

Brake rotor should be checked for cracks, but are pretty durable, from what I've seen from your post they checked the run-out with a dial indicator to indicate a warped rotor, but it won't account for improper torque as they tighten lugs. Road racer's used to heat up the rotors until they were brilliant pumpkin orange at the end of every straight. Glazed pads or rotors can be hit with a scotch brite pad and rebedded. Wish for a positive outcome.

Coming through Colorado in oct I used our brakes hard without the retarder to keep the temp rise down in along grade.

Steering wheel shimmied.  Turned on retarder and with lighter use no brake shimmy.

Three thousand miles later I noticed the coach pulling to the left.

Took it in and the cummins shop said I had warped front rotors with the felt one being worse.

They said they were turnable so that's where we are today.

And I had front seal leaks. 

I would not ASSUME the rotor is bad (or good).  Inspect it, looking particularly for cracks and  run-out.

My rotor was also  brilliant pumpkin red (twice) when I had the slack adjustor issue, which is why Parliament in St. Pete suggested to change it out - not sure what they were worried about, but it was on their dime, not mine, and they wanted to change it to be safe. I forget what the IR meter said when I scanned the rotor when I stopped, but it was a scary high number -

My situation leading up to the initial brake repair was  - no issue with Brake operation, but one pad was excessively worn on passenger rear - probably because of light dragging over time in the past due to slow caliper release, but not enough to make the rotor smell or turn red.

Took in to shop - TN RV did both rear brakes. I drove 60 miles, turned around and came back to TN RV with hot smelly brakes. They "adjusted" the brakes, still hot smelling - but they swore that would go away. Drove to Parliament in St Pete. - they redid the brakes, TN RV paid them to do the job (Good customer service on their part). Stayed Winter in FL.

I drove to IL and back to FL, and the brakes stuck twice on that trip - both times I stopped on side of Expressway to let cool down. I was able to get rotor to release by pumping brake hard while stopped, and it didn't stick again. RED hot both times. Got back to Parliament, they scratched their heads and brought in a mechanic from outside,  The outside mechanic diagnosed the issue as a bad slack adjuster, ordered new slack adjuster, rotor and pads. Put it back together, not problems since.

All said, the inconvenience factor was pretty high, but both Tenn RV and Parliament made good on the costs, so I walked away OK with how it all turned out, and no hard feelings.

Any metals guys on the Forum with an answer as to if rotor is compromised in some fashion due to excessive heat?

Would look for cracks on rotor and see how deep/bad they are,the only thing to cause the cracks would be excessive heat,this
causes metal to become brittle.

On the slack adjuster,never took one apart but I'm assuming yours just wore out.Unless you had a higher priced IR gun you
probably went past the range on your rotor.

Looks like with all the trouble posters have had with brakes lately my advice would be,road test and road test.

I try to remember to stomp on the brakes a couple times before we leave out. It seems to help keep the brakes "limbered up"
Len

Update.

Spent another morning at MOT, and I can finally report SUCCESS!  The steering is now restored to it's former glory, and I am a happy camper.

To continue my tale...we got to MOT at 07:45 and were immediately put into a service bay.  Techs pulled the RF wheel off (again).  Went through a exhaustive check of the rotor, including runout, concentricity and thickness.  Everything checked out OK.  Put the wheel back on, but rotated it 180 degrees from original position ( on the wheel studs).  Then I went for another test drive with Kieth Risch.  He could still feel the pulsation in the steering wheel.  Back to the shop, again removed the wheel.  Kieth said he wanted to get the tire and wheel checked, so he personally ran it over the Herman Power Tire.  They inspected the tire, then put it on their spin balance machine, and found it was unbalanced - so they corrected that.  Back at MOT, wheel was reinstalled, and we went for another test drive.  This time we had success.  The coach was perfectly smooth through the steering wheel at all speeds, and stops GREAT!

Nobody at Mot can really explain why the pulsation appeared in the steering, and how it was related to our "hot brake" incident.  Our wheels have always felt well-balanced to me, yet after the brake locked up, the wheel was not balanced.  We checked to see if some tape-weights had perhaps fallen off the back side of the wheel (from the heat), but that wheel did not have any balance weights attached before the incident.  It is a real head-scratcher, for sure.  Whatever the reason, balancing the wheel fixed it.

To summarize my impression about this whole sequence of events, the original problem was probably due to incomplete purging of the brake caliper.  The young tech apparently followed the proper purging procedure, but did not get the desired result.  When we left NAC headed for home, the RF brake caliper stuck after about an hour on the road.  The other 3 brakes were (and are) fine, so this was a freak occurrence which is not likely to be repeated.  I am sure the young tech will get some retraining on the purging routine.  MOT addressed the situation with a immediate positive response, putting me ahead of other customers, and doing their best to diagnose and correct the malfunction.  While the actual correction process took longer than expected, due in part to the mysterious steering wheel pulsation, in the end they were able to finish the job to my complete and total satisfaction.  They did not charge me anything for the (almost) one full day of extra shop time, and went out of their way to make Jeannie and Bella and I as comfortable as possible while we waited.

I bear no ill will against MOT, and will continue to recommend them to Forum members.  I personally consider this a valuable learning experience.  I now know a great deal more about the braking system on our coach, and that is a good thing.  I now understand the importance of monitoring braking performance and wheel temps, especially after a major brake service job.  If I had taken the simple step of stopping several times to check brake/rotor temps when we first hit the road, I could have probably detected the problem before it became a "emergency".  You can be sure I will be more proactive in this regard in the future.

Bottom line: STUFF HAPPENS.  MOT stepped up and did what was right.  Can't ask for more than that!  ^.^d

Nice outcome for both sides.
Regarding the balance of front tires, I had that done when put the new ones on and the rears too. Yes the stick on weights kinda look bad but I like the fact they are balanced more than the looks.
JohnH

Chuck,
How hot was your tire?
Don't know if these tires have it but sometimes a thin rubber weight patch is factory installed inside so the manufacture can ship a well balanced tire.
Some aircraft tires are balanced this way.
If a tire gets too warm those weight patches can come off and relocate and it will indeed change the balance. Only way to tell is demount the tire and look inside.
I wouldn't do that unless that tire mysteriously goes out of balance again later indicating that weight has moved again.

Don't know!  I wish I'd had the presence of mind to pull out my "temp gun" and check the wheel and tire...but I didn't.

In my defense, I seriously thought something was on fire in the wheel well, and that kinda distracted me.  :o

Chuck,
Hopefully  all is well but I think I would look the tire over at the end of the next few travel days just looking for any sign of a side wall separation. A tread seperation I think you would hear and feel as you drive.

And as the sun sets on Coach Buck City another happy camper hits the trail for home.

Glad to hear it worked out for you guys!
Merry Christmas

We always use the retarder and seeing temps for a short time over 250-300 degrees is acceptable to us and our Transynd fluid.  We would never rely on brakes only as they are our emergency backup in case retarder does not do it for us.  And now Bob & Susan have found another reason to use the retarder.

I use the retarder quite a bit.  Especially in traffic as the brakes cool off after a bit if warmed up.

Had a panic stop last trip.  Brakes fairly cold.  Retarder on. 

Stopped well.  Stops very well if the brakes are warmed up and deglazed without the retarder.

Like a race car with warmed up brakes and the retarder as most here know very well.

Two different owners of 97 m11 cummins have reported different thermostat setup's.

One with and one without a restrictor plate to ensure more coolant to the trans cooler.

Love to see what, if any, the trans temp differences might be with or without the restrictor.

Shop is redoing my warped front rotors and had one wheel seal leaking so it's being done.

Last Update for this thread.

We drove 250 miles today, and the coach steered and braked perfectly.  The wheels all stayed nice and cool - I made several stops to check wheel, tire and rotor temps.  No problems whatsoever.  It took a while to reach the objective, but in the end MOT did a great job.

I want to especially single out Kieth Risch for a big THUMBS UP!  He was the one who would not give up on curing the pulsation in our steering wheel.  If he had not suggested taking the wheel/tire to Herman Power, the final outcome might have been much less satisfactory.

On a separate note, I want to say we are also very happy with our much improved ride.  The new KONI FSD shocks made a noticeable difference, especially on the crappy sections of I-20 going around Dallas.  They seem to be both softer over small sharp impacts, and much more controlled over big bumps.  They're not inexpensive, but they do the job!

Here's some excellent tutorials on how to calibrate your slack adjusters and to check to see if your air brakes are in adjustment.

Good overall air brake system procedures to implement before you head out as part of your start up routine, especially if your coach has been sitting awhile. 

Remember,

Safety First!

Jerry

https://www.youtube.com/watch?v=FDCaDGZKdTQ

https://www.youtube.com/watch?v=ilo4dNE5ELw

https://www.youtube.com/watch?v=rMZwffPGAiQ

Zombie thread alert.

We just got home from AZ and we experienced some ruff roads going through the reservation on 191, so with all the talk about shocks I found an old thread that Berry did on adjusting his. So under the bus I went yesterday and did the adjustment . Will see how they work. And while I was down there I checked the slack adjuster , I first built air to 120 and did three hard brakes then built air back to 120 and did three more.
With my lovely dw assisting I check the free play on the cans and they all came in within spect.

Sorry Chuck,totally lost,Andy if those are the original shocks on a 92 you can adjust them til the cows come home and they will
not be as good as new FSD Konis,they may seem different but are still worn.

That's true John, but they sure don't look like originals the bolts and rubber looked great and none of them showed any signs of leak's. Besides we are not flush with 1200 dollars just not in the budget :))

Aw come on Andy ain't nothing but money😎😎