Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Barry & Cindy on December 14, 2017, 09:55:24 am

Title: disk brake grease
Post by: Barry & Cindy on December 14, 2017, 09:55:24 am
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


Title: Re: disk brake grease
Post by: Carol & Scott on December 14, 2017, 10:03:21 am
Any NLGI Type 1 grease is acceptable.  Grease - Wikipedia (https://en.wikipedia.org/wiki/Grease_)(lubricant)

http://www.beamalarm.com/foretravel-links/PDF/brakes-maintenance-manual-mm4m.pdf
Title: Re: disk brake grease
Post by: John44 on December 14, 2017, 11:16:33 am
Read the Beamalarm part and it states any non-melting grease is good.
Title: Re: disk brake grease
Post by: Chuck & Jeannie on December 14, 2017, 11:33:36 am
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 (http://www.foreforums.com/index.php?topic=29786.0)
Title: Re: disk brake grease
Post by: Travelin' Man (RIP) on December 14, 2017, 11:37:18 am
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."
Title: Re: disk brake grease
Post by: bbeane on December 14, 2017, 11:53:01 am
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.
Title: Re: disk brake grease
Post by: turbojack on December 14, 2017, 01:32:03 pm
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.
Title: Re: disk brake grease
Post by: Travelin' Man (RIP) on December 14, 2017, 02:14:32 pm
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?
Title: Re: disk brake grease
Post by: bogeygolfer on December 15, 2017, 11:09:47 am
Any NLGI Type 1 grease is acceptable.  Grease - Wikipedia (https://en.wikipedia.org/wiki/Grease_)(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.
Title: Re: disk brake grease
Post by: wolfe10 on December 15, 2017, 12:25:57 pm
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.
Title: Re: disk brake grease
Post by: Travelin' Man (RIP) on December 15, 2017, 12:39:42 pm
Can I lube and purge with one tube?
Title: Re: disk brake grease
Post by: craneman on December 15, 2017, 04:22:08 pm
Yes with plenty left over.
Title: Re: disk brake grease
Post by: bbeane on December 15, 2017, 08:49:25 pm
Done right you will use around 1/2 tube.
Title: Re: disk brake grease
Post by: Travelin' Man (RIP) on December 16, 2017, 03:47:07 pm
I do have 3 tubes of Meritor grease, however.

Chris, do you want to sell me one?
Title: Re: disk brake grease
Post by: Chuck & Jeannie on December 16, 2017, 09:22:45 pm
https://www.finditparts.com/products/2128958/meritor-a1779w283
Title: Re: disk brake grease
Post by: bogeygolfer on December 17, 2017, 01:12:01 pm
Sorry T-man, I just saw your post. If you still need some, please PM me and we can figure it out.

Chris
Title: Re: disk brake grease
Post by: qcj on December 17, 2017, 05:15:27 pm
I bought a tube from NAPA.
Title: Re: disk brake grease
Post by: John44 on March 07, 2018, 09:25:54 am
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.