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Topic: disk brake grease (Read 1880 times) previous topic - next topic

disk brake grease

Greasing our Meritor disk brakes continues to be a source of problems because so many experienced techs think they understand what is needed.

We all understand to use Meritor clay-based grease and the purging procedure, but questions arise:

Other greases are successfully being used.  For example, MOT uses an alternative grease.
  What are the characteristics that the correct grease needs to have?
  What does clay-based mean?
  What other grease products meet the needed requirements?
  What are the characteristics of the incorrect grease that we must not use for brakes?

Purging sequence is known, and I known the reason is to keep brake pads from dragging on rotor.
  Why do we need to have brakes purged after greasing?
  What does bad purging or no purging leave behind, and where does it leave that something, that can cause problems?

The reason for the above questions, is so there are understandable reasons to explain to a smart hard-working tech who thinks he understands.  What does he not understand, is the question???

Thanks,
Barry & Cindy


Re: disk brake grease

Reply #2 –
Read the Beamalarm part and it states any non-melting grease is good.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: disk brake grease

Reply #3 –
Quote from: Barry & Cindy –
Purging sequence is known, and I known the reason is to keep brake pads from dragging on rotor.
  Why do we need to have brakes purged after greasing?
  What does bad purging or no purging leave behind, and where does it leave that something, that can cause problems?
For the benefit of our new(er) members, I offer our experience as a example of what can happen when brakes are not properly purged.  This story is not meant as a condemnation of the shop that did the work.  We are all human.  Mistakes can occur at any shop.  I only want our members to be aware of one possible serious consequence of incorrect purging, and offer some insight into ways to avoid getting into the same situation.

Forewarned is forearmed!

Right Front Brake Pads Dragging
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: disk brake grease

Reply #4 –
Print out the pertinent pages of the Meritor manual (or the entire manual) and give them to your tech.

"Only use Meritor specification O-616-A or O-645 grease inside the disc brake caliper. Do not use lithium-base grease, which can melt from high temperatures inside the caliper.  Damage to components can result."

Re: disk brake grease

Reply #5 –
Clay is the base material for the grease.
High temp synthetic greases may be used as long as the old stuff is purged good. Mobile 1 SLC 32 is what I use if memory serves me, I'm sure there are others.
As far as keeping service folks from doing the wrong thing you could replace the grease fittings in the calipers with plugs. The brake lube process is not an annual event unless you run a bunch of miles. I do mine every 2 or 3 years which is probably overdoing it as we only run about 10K per year.
The purging process is used to remove the excess lube leaving a film of grease so the caliper will retract easily. If it's full of grease it can't move freely.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: disk brake grease

Reply #6 –
Quote from: Travelin' Man –
Print out the pertinent pages of the Meritor manual (or the entire manual) and give them to your tech.

"Only use Meritor specification O-616-A or O-645 grease inside the disc brake caliper. Do not use lithium-base grease, which can melt from high temperatures inside the caliper.  Damage to components can result."

When I had my coach in for repairs of the brake by a company that does Houston Fire Truck brakes , I gave them the manual, I highlighted about the grease, which they did not have and had to order.  After all of that they still screwed it up and I ended up gong to Naco & MOT to get them fixed correctly.
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: disk brake grease

Reply #7 –
Quote from: turbojack –
When I had my coach in for repairs of the brake by a company that does Houston Fire Truck brakes , I gave them the manual, I highlighted about the grease, which they did not have and had to order.  After all of that they still screwed it up and I ended up gong to Naco & MOT to get them fixed correctly.

No habla Englais?

Re: disk brake grease

Reply #8 –
Quote from: Carol & Scott –
Any NLGI Type 1 grease is acceptable.  Grease - Wikipedia(lubricant)

http://www.beamalarm.com/foretravel-links/PDF/brakes-maintenance-manual-mm4m.pdf
I just went through this exercise during my last coach service a few weeks ago (which I had done with my local heavy truck repair shop).  I ended up on the phone with Keith Risch at MOT because they used their grease, not my clay-based.  Keith was nice enough to stop what he was doing and research this for me, and confirmed that the NLGI Type 1 grease we used was fine.  I do have 3 tubes of Meritor grease, however.

Chris

On edit: Brett gave me a good suggestion, which is to call Meritor and confirm all this.  I did, but need to get the actual part numbers for my brakes before they will give me an answer.  I'll come back and post their answer here once I receive it.
1996 U295 36' WTBI

Re: disk brake grease

Reply #9 –
Be aware that the correct PURGE PROCEDURE is as important (or perhaps even more so) as is the correct grease.

If one just adds grease, particularly at normal chassis lube intervals, the pads are very likely to not retract from the disks.  Again, all this is covered in the Meritor manual.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: disk brake grease

Reply #11 –
Quote from: Travelin' Man –
Can I lube and purge with one tube?
Yes with plenty left over.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: disk brake grease

Reply #12 –
Done right you will use around 1/2 tube.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: disk brake grease

Reply #15 –
Sorry T-man, I just saw your post. If you still need some, please PM me and we can figure it out.

Chris
1996 U295 36' WTBI

Re: disk brake grease

Reply #16 –
I bought a tube from NAPA.
Chappell & Mary
36' 2004 Foretravel U270 build #6273

Re: disk brake grease

Reply #17 –
Good write-up in the current Motorcader on air brakes,aside from the clay based in the slack adjuster any NLGI grade 1 or 2
lithium based grease is good.
96 U270 BUILD 4810
85 380SL
Drummonds TN.