We received the helper springs and have a local truck mech. scheduled to install and perform maintenance this Monday. I understand that clay based lube is what should be used on the caliper. I looked at the slide pins today and it appears that there is grease, fresh grease, on the fitting on top of the caliper. We had the oil changed and chassis lubed in Phoenix recently and it appears that the tech. may have put the wrong grease in the calipers fitting. I specifically asked the Service Manager if they greased the brakes and he said that they do not. Liability. I told him that only clay based grease should be used there. Could this have caused pad drag on our left front wheel? The grease color around the fitting is an orange/red/purple color.
If the wrong grease has been used how can I get it out before it causes (more) damage? I use the brakes sparingly and have driven from Phoenix to Prescott approx. 120 miles - up hill.
The slide pins look pretty clean. I sprayed a small amount of CorrosionX on the pins.
As usual your thoughts and comments are always appreciated.
Update: It appears if I remove the Reliefe Valve from the caliper I should be able to force out the bad stuff with the good?????
Scott,
If the wrong grease has been used on the calipers, it needs to be purged asap. This page from Barry Beams sight will explain better than I can and will show you the clay based grease to be used. Brake Maintenance [ForeForums Foretravel Motorcoach Wiki] (https://wiki.foreforums.com/doku.php?id=technical:brakes:maintenance)
I don't believe you've done any damage yet and forcing the wrong grease out should help the situation. George Hatfield had this same problem and did a great write up with pics on this subject. Wrong grease in brakes (http://www.foreforums.com/index.php?topic=14946.0)
Hope this helps,
Jerry aka Murph
Thanks Murph -
Hadn't found George H's thread. Found maint. stuff on Barry's site though.
Update: Read George's thread. I will chat with the mech. and attempt to purge the red stuff out with the good - clay based. Hope he has some in his shop.
Thanks again - Ya'll :)
Every mechanic, even the best will shoot some grease into every zerk grease fitting he sees. It is their natural extinct. Even if they are told to skip brake lube, and agree, they have no idea what we are asking.
Very very very few mechanics have ever seen a Meritor disk air brake, so they have no reason to skip brake zerk fittings.
We now have small cable ties wrapped around each of the 3 brake zerks so at least the tech MAY ask why the ties are there.
The wrong grease and the wrong purging procedure cause so much damage, it pays to do something to protect our brakes.
ARGH.....................
@Scott I don't think there has been enough time to cause any damage. Since the mechanic is coming to do the brake helper springs have him push the clay based grease through and you will be good. If you have trouble finding the grease call around to the fire stations in the area and ask where they have their brakes serviced and then call those shops and see if they have it. You may have to drive to Phoenix but at least you will be able to sleep at night!
see ya
ken
It will take a full tube to purge all the brakes. I had cummins do mine and they had another FT in and the guy used the wrong grease. They pulled everything and washed it and applied the proper grease and gave me the extra tubes for my troubles. Over zealous mechanic did it after saying not to. I had just changed over to Synthetic too. Oh well I have a couple more tubes of it. They only sell it in 12 tube boxes, so out motorcade group bought a box and split it up.
Scott,
I just finished the same project. I had my trans serviced awhile back and they told me when finished they had greased the calipers and driveshaft. I cant say the grease caused the problem as the pins appeared to have something like maybe anti seize on them.
I would try to locate the grease as soon as possible. Atlanta has a lot of truck parts and Maintenance facilities, but locating the grease proved to be a much bigger problem at a local shop then finding Meritor parts.
Scott, you may want to check the specs on the grease they put in. It might be just fine. I believe it is all about temperature ratings. The parts guys at MOT told me this.
Also, I think the pins are better left dry with no lubricant.
Ken - I did not sleep well last night.
Thanks for the thoughts guys. I will contact Rocky Mountain Cummins, as they performed the lube and check on temp rating of the lube they used. I will also check with local fire depts and check the other stuff.
I am guessing I could have a couple of tubes sent from FOT. Will Check on Monday. Should be pulling out for southern Utah on Tues. Will probably have to change plans.
Thanks again.
I've had the same thing happen even after explicit instructions to avoid greasing those zerks. Even had them painted red and had the service writer highlight the instructions. In that case I had FT fix it. They just forced out the wrong grease with the gray stuff. However, I agree with Old Hippie and think we are making way too much out of this requirement.
jor
I am not a big believer in coincidence as we encountered brake drag while on a short drive the other day. But.......................Sent an email to Meritor requesting more info and local service centers. Will post results.
Scott, look for a shop that works on fire trucks,a lot of them have the same brakes we do.
Chassis lube is a super easy job and requires very little physical strength, flexibility, or technical knowledge. Anyone who can get on a creeper and roll under the coach should be able to wipe off the grease fittings and squeeze some grease in using a one hand pistol grip grease gun with a flexible hose. There aren't very many fittings so the whole job can be done in a few minutes. I just did it the other day in the parking lot at work just before I left on a trip. I think the majority of readers on this forum should be able to do this job themselves, just saying. Why pay someone else to mess up your coach?
One thing I discovered on my coach is that there are two fittings on opposite sides of the cross in each of the universal joints on the driveshaft. I greased them both even though I took a wild guess that only one of them needed to be greased. I figured they put two fittings on opposite each other so one of them would always be pointed down. I asked Stewart & Stevenson and Foretravel this question and they both agreed that only one of the fittings needs to be greased, whichever one is easiest to reach. Greasing both fittings doubles the chance of accidentally getting dirt into one of the fittings... Other than that everything else is just like greasing fittings on any other piece of equipment you've ever greased in your entire life... Super easy stuff folks.
Should someone on this forum write up a chassis lube tutorial with photos? ...or is there one on here already?
Mobil 28 is a clay based synthetic and I used it for my brakes. It is a bright red color. It is also readily availible
Google (https://www.google.com/#q=mobil+28)
http://www.exxonmobil.com/Belgium-English/Aviation/PDS/GLXXENAVIEMMobilgrease_28.aspx (http://www.exxonmobil.com/Belgium-English/Aviation/PDS/GLXXENAVIEMMobilgrease_28.aspx)
Good luck,
Rick
Scott is correct on easy & simple, why I trust no one to grease my coach. Also I have only used silicone grease on all including caliper fittings. Yes added springs, at 104 k miles, everything looks & smells like new. Understanding how to grease the calipers is a biggie.
The silicone beats the temp requirement per the clay based grease. IF it or my procedure was at fault, I would expect an issue, but so far I am the happy puppy doing it all the wrong way per the "Experts"
RE: check on temp rating of the lube they used
In my opinion, the wrong grease, while it may not hold up to higher temps, is not the major cause of brake damage. Damage comes from not purging out excess grease, which causes the caliper to not fully 'relax', causing them to keep too much pressure on the rotor.
Another point is that the brakes only need to be lubed once or twice during their lifetime according to Meritor.
jor
Barry is correct on improper caring for the caliper grease/over greasing will cause it to drag, also important is the slack adjuster / adjustment. Seems there are a few who have little clue to the requirements, and should relay on outside service. Me, I trust no one on my brakes & wheel bearings, been playing with wrenches too long and seen too many idiots playing mechanic.
Most of us have opinions.
I use Mobile SHC 32 synthetic clay base for the brake calipers it is red as well. I agree with Barry most likely more problems are caused by improper purging, and mechanics "greasing the fitting". I talked to Meritor a while back while the person on the other end of the phone, didn't positively say OK, he indicated that a quality synthetic high temp grease would do just fine, as long as any old grease was purged.
I made a copy of the U320 lubrication diagram with a DO NOT GREASE BRAKE CALIPER FITTINGS written in red on it which I give it to the tech.
It should be in your manual. If anyone wants a copy I will look for it and post it here.
Keith
Had the helper springs installed yesterday for a local mechanic. He had performed maintenance and stuff on the local FD equipment. The lube that Cummins used is Rated: NLGI, Grade 2 with a temp rating to 375 deg. F. I contacted Meritor's Help line and they stated the spec is: NLGI, Grade, 1 with a heat rating of 310/340Deg. F. They advised that the Grade 2 with temp to 375 would be OK. It is my understanding that nay Grade 1 lube will work and some grade 2s if the heat spec meets or exceeds the Meritor spec. The difference being - the viscosity of the grade 2 is thicker than the grade 1. Grade 2 is considered to have the viscosity of peanut butter and the grade 1 is as tomato paste. So grade 1 flows easier. With the newer lubes available I understand that the overriding concern is heat so the grade 2 if it's spec meets or exceeds the 310/340 Deg. range it will work. When we get to Montana I will acquire some Grade 1 lube and purge and re-lube the calipers. Drove from Prescott, AZ today to Glendale, UT and rarely used the brakes. Between the retarder and gear changes the only time I touched the brakes was when we came to a stop - less than 5 mph. He also cleaned the slide pins and adjusted the slack adjusters.
I do not believe in fate but - the left rear had been dragging and the pads will have to be replaced when we get to Montana next month. He said we had about two to three thousand miles left before we damage the rotor - don't want to do that. He could have changed them for us today but we wanted to get on the road.
Thanks again for your interest and input.
Oh - $20/spring kit and $80.00/hour to install. Total just over $400.00. Are they absolutely necessary? I don't know. I feel better now so I guess the cost was worth it.
@Scott Glad to hear you got everything straighten out. You'll sleep better tonight!
see ya
ken
After the wrong grease almost got into my brakes a couple of years ago at the local Tucson Inland Kenworth, I put wire ties on all the brake grease nipples. Of course I also tell them not to do it.
George
Ken - Hope to sleep better tonight. We are in a nice valley with green grass in a nice little park. I still am feeling your pain. Wish I could help.
George - After I purge and put in the correct stuff I will probably wire tie it as well. It often seems like important information, regardless how well meaning people are, often gets lost. BTW - hows the knee?
I am confused about adding helper springs. To add helper springs, the wheels are removed and slide pins need to be removed, and if slide pins are removed, they should be inspected, cleaned and replaced if pitted (& in our case we spray and wipe with CorrosionX). So if the slide pins were cleaned & inspected, it is absolutely worth $400. We thinks slide pins should be cleaned every 2-3 years or so. Brake pads move on slide pins and if they hang up, costs can be high to fix.
Springs are a nice add, but not required, and will not fix a problem brake. We added springs when we did our last brake inspection & lube.
I don't see any reason to re-grease brakes if a high temp grease was used AND PURGED. Brakes probably only need to be greased about 3 or 4 years and Meritor says only couple times in their lifetime, but who knows what a brake lifetime is, especially with Allison retarded installed. Our original pads are still looking like new with 150,000 miles.
Why do you think your left rear is dragging?
My opinion !! I do not really know what to believe, but never had any hang up on brakes so do not know what to do. I spray now and again with dry silicone lube spray and before this trip they looked great.??
JohnH
Are there any images or videos for how to adjust slack adjusters and purge grease. Just wanting to make absolutely sure I don't create a problem on what are right now functional brakes!
yes there is a long video on the Meritor site showing all the aspects of the brakes.
JohnH
The attached may help.
Had the brake caliper lube purged and replaced with the right Grade #1 stuff at Peterbuilt in Missoula - $119.00. Although it is true that a grade #2 lube may meet the specs, there are 3 things the spec calls for. High temp, low temp and lube viscosity. Many grade #2 lubes meet the Meritor specs. Not sure if the low temp requirement is important to us as we will probably not see subzero temps while under way. When the tech checked the slack adjusters after the purge and re-lube he stated that the slack adjusters were set correctly. He also stated that our brakes looked almost new.
Thanks to George's thread recently, I was aware of the clay based and had ours done with it. The service company did not have and had to special order it. I printed off the pages from Barry's site and hand delivered to the service advisor to ensure accuracy. They were also appreciative of the diagram as they had not seen the disc brakes before.
David
David - nice to hear you dodged that bullet. ;D
Scott - was it Montana Peterbilt you had do the work in Missoula? I called them today to see about purging red grease from our brakes but the service fellow I talked to didn't recall working on a motorhome and said they have only started working on Meritor air disk brakes on trucks recently... If this is the right place I'll call back and try for a different fellow.
Background - I had the oil changed in Kalispell; I had asked for NO chassis lubrication but found the tech busily greasing before I stopped him; I thought I had stopped him before he got to the brakes.
A few weeks (300 miles) later I was going to have RnR in Liberty Lake, WA, inspect and lube the brakes but once the coach was up on the hoist they informed me that all 4 brakes had red grease on the nipples and it would be a 10 hour job to take all the calipers apart, purge the grease and check to see if new parts were required ($2600 was the worst case estimate for parts if all new parts required – which they doubted). He did say the brake pads looked good.
The RnR tech has been working on Foretravel chassis for some years and seemed to know his stuff (although didn't know about Meritor helper springs).
With a $1000
+ cost estimate, I thought I'd do some more research first. I've been looking at FF posts and the Meritor website trying to learn a bit more about brakes and what is required to get rid of the dreaded red grease. It seems from FF posts that the red grease can be forced out with the proper grease and, as long as excess grease is purged, all can be good. Now it's to find someone to do it properly... (the coach is back in Kalispell until we head south in September).
That would likely be Luke. He does know Foretravels and is a decent guy who seems to care. When I had an issue he couldn't solve, he called FOT to get an answer...and when the answer was WRONG, he considered it a while and called FOT back and got a "lower" tech to tell him the right way to fix my issue (about 10% of the cost that FOT had initially suggested). RnR may cost a little more than some, but I trust Luke to fix things and fix them right.
Grant I PM'd you. Give me a call and I will explain who did what and where. ;D
Brad - the fellow working on FT chassis (at least on mine) was Rich and had a number of years experience with FT; Luke was also in the shop but seemed to have a different FT specialty. Yes RnR seemed quite competent; I thought I'd do some more checking before I proceeded. We won't be going back that way until next summer though.
Scott - thanks for all the info. I'll post the results when I have some (likely late September).
Mobil 28 grease is RED and appropriate for the calipers.
Good luck,
I did not look into Mobil 28 Red. :D
Thanks Rick. I called the shop that did the oil change. They confirmed they had used a grade 2 grease.
The same thing I use. I did talk to Meritor a while back about caliper grease. While they did not come right out and say it, he indicated that synthetic grease is fine as long as the temp specs are the same.
Just as important, maybe more so, is the purging of excess grease from the caliper.
If all excess grease is not purged the calipers will hydro lock.
The shop manual I think shows a bleed valve that needs to be open when filling with grease.
Plus retract the pads in the process?
I remove the top grease fitting/plug, and cycle the caliper pistons all the way in, then back out. Then replace the fitting.
Have you guys ever looked at the calipers? They have a spring loaded bleed valve that bleeds all the grease out when retracted. Well, at least mine does. Maybe older years don't. This is approaching old wive's tale. It's not that complicated. I greased my rears, then turned parking brake off...it squirted all the extra out. Cycled it a few more times and more came out. 20,000 miles later, no problems.
It is inconvenient and a little scary when a tech lubes your calipers with the wrong stuff especially when told not to and you find out later. If NLGI Grade 2 is used (normal chassis lube) your brakes will not give out unless you are driving in extreme heat or cold.
From Mobil's web site showing charismatics of different NLGI Grades.
http://www.mobil.com/USA-English/Lubes/PDS/GLXXENGRSMOMobilux_EP.aspx
Operating Range for Grade 1 is: -40 C (- 40 F) to 150 C (302 F)
Operating range for Grade 2 is: –30 to +110 °C (–20 to +230 °F
The viscosity is also thinner in Grade 1 than 2. Grade 1 is like tomato paste and Grade 2 is more like peanut butter.
No wives tale -
We have done what others have suggested - We put Zip Ties around the Zerk fittings and always advise the Service Writer and the Tech about them.
No mystery - Just must be aware and act accordingly. Many have had the wrong lube applied and no disasters yet. Follow Meritor's instructions for purging.
http://www.beamalarm.com/foretravel-links/PDF/brakes-maintenance-manual-mm4m.pdf See page 50.
When this happened to us I took the above Meritor Maintenance Manual with us to the Truck Service Center to make sure they understood the procedure. Not rocket science. :-D
As has happened to others, even after explicit instructions, I ended up with chassis lube in the brakes. Foretravel simply relubed the with the clay based stuff. No disassembly.
jor
That's what we did too. Relube to purge the Grade 2 out. Nothing else.
Re greasing u joints, always grease BOTH grease nipple in a u joint, after wiping any dirt, dust off the fitting...that is the standard procedure in the trucking industry.
Not sure I understand, since both grease nipples/channels lead to exactly the same center section of the U joint. As long as clean grease comes out all 4 grease cups, don't see why it would make a difference.
The key is to see grease at all 4 cups. I find it easier to achieve by lubing both nipples.
Incompatible greases, clay and lithium/soap-based greases for example, may chemically interact, causing a runny mess, per a tractor forum post.
I posted a grease compatibility chart in another thread.
Totally agree. I recommend choosing A (like ONE) grease for the chassis and sticking with it for the life of your coach. Whether you do your one lube or have others do it, if you have a good quality manual grease gun and a copy of the lube points for your coach, you are good to go.
I chose a grease that met the chassis's specs and bought a case of it. 18 years later, still have one tube left.
Yes, the disk brakes take a different lube. And, were it me and I relied on others to grease the chassis, after the application of the proper grease to the brakes, I would remove the zirks and install plugs. Remember, the brakes do NOT need routine lubing.
Yes, on EDIT changed routing to routine. Thanks. The other Brett.
Brett means ROUTINE lubing!