Went by the shop doing the repairs to my brakes. The slide pins had become corroded and prevented the outer caliper from retracting. The drive axle rotors had got so hot that there are a great many small cracks in them. They may have been able to save one rear disc through resurfacing. But those cracks mean new disc's. The front rotors, Bearings & axles look great. But as the fronts had to also do the work of the rears. The friction material had also become hot and had a crack in the middle.
I told the shop that even though the fronts look fine I want new slide pins in those as well.
So far $1,300 in parts. Which includes:
Two rotors
two slide pin kits for rear axle
four sets of pads
slide pin assist springs
Shop will need to order two more slide pins kits and springs for the steer axle.
The Meritor warehouse in Spokane, Washington said that these brakes are the same as Spokane's and a great many other cities transit buses. Calipers, pads and rotors are same for all wheel positions.
Should get the coach back next Tuesday or Wednesday.
After you get your coach back, I urge extra caution on the first few drives at highway speed. Stop occasionally to check brake and wheel temps with a non-contact infrared thermometer...just to make sure everything was put back together properly, and is performing correctly. Doesn't take long, and may save you big problems down the road.
Might consider getting the shop's recommendations for seasoning the new pads. As you know it's an important step for brakes on a performance car. No idea of what's recommended on a coach.
The Meritor pads do smoke upon first use in my experience. Whether or not my Cummins dealer did the job correctly which I think they did as I watched them most of the way through the new rear pads and rotors had a lot of smoke on first hard use.
They may not have degreased the pads and rotors adequately was my thought.
Each time in use the smells lessened and the brakes worked better and better.
I alternate between the brakes and retarder and downshifting the motor just to spread the work out and not overheat anything.
Coming down a 13 mile grade out of the la mountains Friday I got some brake smell as expected.
Just don't overdue it would be my suggestion
Normal use after a couple medium to hard stops (but not over use) is all that is needed. Our brakes were designed for trucks weighing much, much more than our coaches. The death knell of the brakes on our coaches is one of underuse/disuse causing the slide pins to corrode and stick than being overused.
I never ever wore out the friction material on any of my class 8 tractors. (Mack CH, Mack vision, Kenworth W900) pulling doubles. When I bought each of my trucks. I simply got in them and drove them. I didn't go trough any sort of initiation ritual and I went ten years with ONE breakdown and that was a micro fracture on a turbo impeller that caused it to explode. I typically had 400,000-450,000 trouble free miles on them when traded in
When Brett inspected my coach prior to purchase, the right front brake had more wear that the rest fo the brakes. Next year will be a brake job for sure. Not sure if its something I want to do though considering the importance of what they do....
I have just under 100k and the linings are barely worn. I talked to Ron, the PO and he said with the retarder and proper use they just don't wear out.
I agree-- unlikely to wear them out from use.
MUCH more likely to have them wear out from "lazy side" hanging up. That is why keeping slide pins in good condition is important.
Also why Meritor came out with the springs to help force the lazy side to retract (which I recommend).
When I went to the shop to check out the brakes after they were apart. I saw on the front brake that the caliper simply rotates on the second slide pin after the other was removed and gives full access to the pads. You have to deal with a very heavy wheel/tire combo and have a very robust safety stand that you trust. As well as knowing how to reset the automatic slack adjusters.
Bear in mind that I didn't see them do this procedure. I was just looking at the end result. So it may be more difficult than it appears.
Got the coach back today.
In addition to the brakes. I figured while the wheels and rotors were off. May as well replace the seals all around. Axle bearings were in excellent condition.
$1,600 in parts and $1,400 labor.
I hope this fix it marathon I have been on slows down a bit.
My rotors show tiny cracks thruout the pad contact area -I assumed this was a normal occurance due to the type of cast iron used as all four rotors are basically identical - cracks everywhere.
Maybe at this time, it might be wise to take a deep breath, and revaluate the seals, doesn't seem like since everything is apart the vendor is giving you a discount on this work, at this point it may be to your advantage to renogiate the costs as they appear to be highly inflated based on convenience. I could be totally off base on this issue, but felt the need to respond. Hopefully somebody else can provide input.
Might be helpful: Bendix (not Meritor) air disk brake rotor inspection guide:
Mine are the small ones they say are OK. thanks for posting that!
Well. When i called Foretravel parts department. The cost of parts was $2,300 plus shipping on those heavy rotors and pads. that was without the new axle seals front & rear. I asked my shop to replace those seals. They never suggested it.
One year ago, discovered inside oil seal leaking. I found this while under my rv replacing the generator fuel line. I had Kaiser Wheel and Brake in Eugene, OR., complete the repair.
As I did not know the service history, of my, new to me Foretravel, they recommended taking apart the calipers, cleaning the pins, using the grey clay grease, and installing spring kits while they had everything off to replace the two front seals. I did this. They said the pads and rotors were fine. They also recommended cleaning and doing the same with the rear calipers (cleaning, grease, spring kits). I just completed that this past week, a year later. As the front was a year ago, the rear pads and rotors were fine.
I have used this shop for over 15 years, have always been pleased with their service and recommendations.
Sorry bigdog, i think i misread this as an extra $1600 & 1400 just for the seal portion.
Dang! That would have been hi-way robbery for sure. :))
And what's strange is that given my problems with the lazy side not retracting. The shop showed me my slide pins and they were fine. No corrosion and miked out fine as well. The slide pin bushings however were shot from a life of no lubrication. So all slide pin bushings were installed and clay greased
The passenger rear brakes were the worst. The outside pad had worn down to the metal. (which looked to be the steel see through stuff used on outdoors stairs) but not the actual pad mount. The opposite side still had friction material, But way less than the inside pad. Both rear rotors had lots of out of spec cracks from getting very hot. All remaining pads on the coach had two sizable cracks in them from heat.
Having gone through a major brake refurbishment ourselves not too long ago, I am always very interested in reading about "brake issues". I have noticed in numerous threads that the right rear (passenger side rear) brake is in many cases the one with the most wear/damage/problems. In our case, the right rear corner required a new rotor, new pads, and a new axel seal. The other 3 corners had much less rotor wear, and we got away with new pads. I also had new new slide pins and helper springs installed all around, but that was a voluntary preventative maintenance measure.
Anyway, I'm just wondering why the right rear corner would be so apt to have problems? I would think the front brakes would carry most of the braking load, but there must be something about that passenger side rear corner that induces excessive wear.
This thread has me more than a little freaked out. I ASSUMED brake work had been done on Brett's/ours, but can find nothing in the files indicating so. Hard to believe in 170,000 miles NOTHING has been done! :facepalm: Can the brakes be checked out by just a visual inspection, or do the wheels have to come off to get to 'the heart of the matter' ?
Mike,
I think the wheels will have to come off. With wheels in place, all you can really see is the inboard surface of the rotor, and the bottom slide pin. To get a look at the (critical) brake pads, outboard rotor surface, and top slide pin, you need to pull the wheels. Sorry 'bout that.
Edit: You
can gauge the amount of wear on the pads by measuring the slide pin length that is exposed. (Photo below of front brake)
See Section 13, Page 53 in Meritor manual:
http://beamalarm.com/foretravel-links/PDF/brakes-maintenance-manual-mm4m.pdf
[quote author=Chuck & Jeannie link=msg=326253 date=1537633846 I think the wheels will have to come off. With wheels in place, all you can really see is the inboard surface of the rotor, and the bottom slide pin. To get a look at the (critical) brake pads, outboard rotor surface, and top slide pin, you need to pull the wheels. Sorry 'bout that. Edit: You can gauge the amount of wear on the pads by measuring the slide pin length that is exposed. /quote]
Thanks, Chuck, sorta figured that the wheels had to come off. :facepalm: Reading the manual (thank you) and going through the files again of Brett and the POAB (previous owner after Brett) I'll get more of a grip. They seem to work fine, no noises, tho have never had to 'dynamite' them. I have a feeling that using the Pac Brake a lot has plenty to do with the brake life b^.^d
The U225 and U240 have completely different brakes.
They are wedge design drum brakes. Much less problematic than air disks (and, yes a little less braking force). Lots of medium duty trucks in U.S. and Europe used that design.
Mike,
Disregard everything I said...
Do not lube the pins
I always thought we'd have disk brakes: looks like what we have are old time drum & shoe!
Mike you might want to start squirreling some money away for rear pads, and save a couple of hundred bucks and have it done when they put on your new tires. There are some ports on the backing plate where you can see how thick the pads are pita on the rear, may need flashlight and a mirror. Rear pads are where most of the wear occurs.
Hmm, I called my small house a 'pad' in the sixties, but I've always called drum brakes 'shoes'. Are we on the same track or:
Yes, shoes, brain phart soo used to disks
Comprende. I'm still going through my files and I'm sure Brett is, too. Hard to fathom, in 170,000 miles, this coach has had NO brake work???
No brake work (in terms of shoes/pads) on any vehicle I have ever owned.
One reason for the PRXB exhaust brake!
Unless subsequent owner overheated them, probably still in very fine condition.
Our retarder is abrupt at low speeds. Like the service brakes better
This is an interesting thread. Two of the three disk brake models that I've had showed very little pad wear. Those two had the Allison retarder. Our 95 had to have major brake work - rotors and pads. That coach was a 40 footer with an M11 and a Jake brake. When I got it, the Jake was a one speed, all six cylinders to 4th gear. It was not a good setup and was not enjoyable driving in the mountains. I had it changed to 5th gear and two speeds which made it really nice (almost as nice as a transmission retarder). I think the single speed 4th gear setup caused the previous owner to lay on those brakes much more than you would prefer and ended up really heating them up many times.
jor
VERY likely!
Different driving styles call for different engine/exhaust brake programming. Rarely have I found that factory settings meet my spes.
Perhaps they are meant for "Americans"-- we only drive automatics and only drive with the transmission in "D".
Sorry, can't do that. Listening to the machine says a knowledgeable driver is better than a pre-set program. Pre-set programming can not know that you are about to to hit a 7% grade and you need to downshift early to prevent "running right through 5th gear to 4th". Downshifting manually to 5th and putting the hammer down and 5th is a good choice.
Same for downshifting program for exhaust/engine brake. Take the down grade on I40 into Albuquerque. 5th gear exhaust brake and you are good for the full 14 mile run. 4th gear and you are "over-braking"/accelerating all the way down. But 5th gear pre-select says you have to be willing to use the down arrow when you need to go slower.
The good news (VERY good news) is that you can have the Allison reprogrammed to any pre-select gear. Takes about 15 minutes at any Allison dealer.
Old time? It's certainly how I feel some mornings.
I'm in the process of putting brake pads on drivers
And I could use a little guidance!!
Mainly a couple of questions
1 can I heat the torque plate arm
Picture with finger pointing
2 can I buy a boot for the slack adjuster rod
Thanks
Chris
As a added note I used a air hammer to get top one loose but bottom don't want to move
I have been soaking it in PB blaster
Chris
Chris,
1. I have never had to and would avoid it at all cost. If you warp, crack, distort that piece in any way the guide pin will be out of alignment. This will cause the guide pins to bind. Have you taken a 4# hammer and massaged the end of that nut that is backed off to loosen up the slide pin retainer? That slide pin retainer needs to be depressed to get the slide pin out and by the looks of it the retainer is not in the down possession to be able to release the guide pin.
2. Have never looked for one as once they have road grime in the adjuster we just replace the adjuster.
Mike
Mike, Thanks I was reluctant to do any heating, been using a air hammer while holding retainer pin in to no avail. Will Try chucks approach and use a bolt with deep wall socket to pull pin. I soaked it down with penetrating oil and will let set overnight.
Chris
Chuck,
That has been the best way for me also if the guide pin is stuck. Hope you don't have a bur pulled up on the slide pin from the slide retaining pin nut being overtightened.
Mike
When David at NMS did mine he had a puller like this:
Amazon.com: OEMTOOLS 27085 Slide Hammer Bearing Puller Set: Home Improvement (https://www.amazon.com/OEMTOOLS-27085-Hammer-Bearing-Puller/dp/B004FEPDCM)
but had a threaded end that he screwed into the threads of the caliper slide pins. They came out pretty easy with that. Not sure if he made the tool or if it's available to buy.
This is what got mine out.
helper springs (http://www.foreforums.com/index.php?topic=31008.msg271462#msg271462)
Chris,
Had another thought on this that may help you out. Take a pair of pliers and carefully twist the slide pin retainer. You don't want to bugger the threads up or you will have to replace it for sure. The reason being is the flat that is on the retainer pin may be slightly off causing the slide pin to be in a bind. I have had this happen in the past but not often as there isn't much wiggle/twist room for the pin.
Mike