I'm planning on having my brakes inspected and trying to decide between taking it to a shop or having a mobile mechanic come to my house and look at them. I'm leaning towards the mobile mechanic as I hope to be there with him and maybe get a little education on the brake system Plus I don't have to drive it somewhere and leave it. He specializes in heavy truck repair. I'm seeking advice from the group on what to look for to help minimize my chances of being taken advantage of. I'm not having a problem with the brakes, I just want to get them inspected.TIA
Just make sure who ever you use is familiar with disk brakes.
First thing I would suggest is to look at the thickness of the disc brake pad linings. If you have a lot of lining left that would indicate that your brakes are probably functioning OK and wouldn't require major work. Don't be surprised that the inboard and outboard pads are different thickness as they come that way new. The pad thickness/wear should be similar on opposite sides of the same axle. A thorough brake inspection should include pulling/inspecting/lubricating the slide pins and this is not difficult to do unless they are seized up. The slide pins should come out easily and have a smooth and polished surface with little or no pitting. If they are seized or heavily pitted they should be replaced and they are fairly expensive. Meritor calls for a light coat of WD40 only for lubricating them.
This is definitely a case of "Knowledge is Power".
Highly unlikely the mobile mechanic has seen air disk brakes -especially on a 30 year old vehicle. There nothing difficult about them; just not used in trucks back then; I think mostly fire trucks and similar emergency vehicles and of course, Foretravels. Probably the only motorhome manufacture to use them back then.
The mobile mechanic might be good or he might not be. I think it's worth a shot, but you will need to find out on your own. With some knowledge you can gain by researching you can find out if he is trying to snow job you or not. For instance, I would ask him what kind of grease he would use on the brakes (hint: it's not normal chassis grease). If he has never worked on Air Disks he should own up to it and tell you how he will approach it. I don't think it's a problem is he hasn't, but he shouldn't be deceptive about it.
Fortunately there is good information on air disc brakes with photos showing what's OK and what needs replacing.
The forum library has the information here (see Air Disk Brake Maintenance.pdf and Meritor Disk Brake Maintenance Manual):
Air Brakes (http://www.foreforums.com/index.php?action=media;sa=album;in=470)
You should be able to see the surface of the rotors and even the wear of the pads (via the exposed length of pin) by just by looking around with a flashlight.
I would also suggest using the search feature in the forum. There a lot of threads on brakes and the correct grease to use and why.
Here's an old post from someone with a 1993: Does anyone have the part number for disc brake pads for my 1993 unihome? (http://www.foreforums.com/index.php?topic=24822.0)
It looks like a lot of the links a broken but there's still good information. I noticed the P/N I had for front pads has been replaced with this one (KIT15627PM) : http://www.meritorpartsxpress.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10154&urlRequestType=Base&partNumber=KIT15627PM&langId=-1&catalogId=10051
Might also try the air brake holding test. It's something that you can do before he shows up. I don't want to quote the wrong numbers but you should be able to find it on the forum.
Something like press on the brake and it'll drop 5 lbs or so and the hold pressure for 2 minutes ?
Ours wasn't holding air so I had a Mobil mechanic replace the rears with piggy backs and the fronts got new "dog bowls" (his term). The rears were the problem with a few small holes but the fronts were not leaking yet. BUT.. the fronts were cracked similar to how our tires would look when they need replacing. So of course he replaced them also.
Parts for the piggy backs were about $100.00 each. I did buy the complete air brake canister but left the part of the brake can attached to the coach in place. Hence the piggy back term. ( you tube). The little rubber dog bowl things are cheap, like $6.00 bucks each.
Do watch the mechanic while he's doing this ( if you need it) you'll get a great education along with lots of you tube videos helps.
Also it seems our Foretravel's have about the smallest air disk brake systems out there. My brake cans in back were 20/30s and 30/30s are way more common. The fronts are even smaller. At least on a Grand Villa U280.
Labor for the service was $300.00 and I bought all the parts.
A couple of pics to follow up on previous post.
Use correct high temp grease, then purge it all out. Use CorrosionX on slide pins.
Other than the special Bentonite thickened high temperature grease you need to use, here's some solid information we all need to know.
https://www.fmcsa.dot.gov/sites/fmcsa.dot.gov/files/docs/brake_safety_systems_02-14.pdf
The pins collect road grime and if you operate on dirty roads they will also collect road salts. I prefer to remove and clean bores and shafts. Wd40 and reassemble every couple of years for me. They can be a real bear to remove the first time but should be fine after. I use anti seize inside of the mount on the lock cam. Not so much about the lock wedge than the jst the opening. Corrosion pitting will be in the exposed areas and look like new were they are in the bore. Install the helper springs. Cheap insurance IMO. Once you get them up to speed next service wont be as bad. Ive seen rear lower pins you would have thought were frozen in place never to be removed again. They all come out eventually.
Yup, your air disk brakes are unique, but not difficult to service.
But it is critical that it be done correctly-- correct grease, correct grease purge procedure and check the slide pins carefully. If pitted, replace them. If good just lube LIGHTLY as mentioned above.
I would absolutely recommend AGAINST using anyone who is not familiar with air disk brakes. Check with your local fire station to see who services theirs.
I would have misgivings about a mobile mechanic having experience with air disc brakes. I second Brett's suggestion on asking at the local fire station who does their brakes even though when I needed to do mine I did not take his advice which I should have. Most truck repair places only know drum brakes and only to replace parts. At least in my experience it didn't turn out well for me to get somebody else to do it, and instead invest in the tools and knowledge and time to try to work on it yourself if possible.
So your telling me that in 2024 most trucks still run drum brakes ?