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Tag Axle Bearing Oil Overheating
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Thank you Tim, I just left them a message and hopefully they’ll give me a call back soon.
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What was going on with the brakes? I would like to know so I can check mine?
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Andy, you may want to call Prevost PASS (Prevost Action Service System), if you haven’t done so already. They will be able to recommend service facilities closest to your current location. We had a similar incident in WI last year and they were extremely helpful.
800-463-7738
Good luck…
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I have used S & S Denver for front brake repair, Rotors and pads, because of me not inspecting them often enough, they have excellent service in the bus repair bays. Had parts in stock, And I don’t remember their cost being any greater than prevost,,and called me several days after we left there and said they had over charged me and would refund the overage, I got NO complaints on S & S Denver
Glenn
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By Jon – First, was the coach recently lubricated? I ask that because the Meritor brakes when overgreased can hang up or drag. A dragging brake can generate a lot of heat.
This is important, if the Meritor is greased wrong as Jon pointed out you can have dragging brakes. I had both front rotors years ago ruined for this same reason, the shop over greased.
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Good one Tom, when I did mine I backed off all the way greased and turn all the way tight and it pumps all the extra grease out. I was scarred when I did it. If you don’t pump all the extra grease it will drag.
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How many MH owners with Meritor disc brakes know what the grease spec is for the calipers, slack adjusters, slide pins, etc on their rig?
Here’s the mx manual for the Meritor disc brakes. See p.62 for the spec. -
To answer some of the questions posed above.
- The brakes were inspected in April 2019 at ETLCETLC. I do not know if that included lubricating or not but I would assume that that is part of their routine annual maintenance.
- The bearings were not messed with and the hub fluid level was correct. I am not sure when the fluid was last changed.
If the cause was over greasing then I have to wonder about the other brakes. I do find it interesting that if the brakes were dragging they must have been barely dragging because there was no obvious abnormal smell that either my wife or I could detect.
I’ve contacted S&S Denver and they have not yet returned my call.
I also contacted the Prevost Regional Sales Manager and he was very quick to get back to me and recommended Arrow Stage Lines (Jason Harris) in the Denver area and he could not get me in this week and next week was iffy. Those in the Denver area may want to consider them but I have no experience with them.
We are heading to Santa Fe from here so I asked about a service center there and I was given All Aboard America in Santa Fe (Jason Summers) but they have not returned my call yet either.
While at the “Slick Spot” repair shop in Ft Morgan, CO I had them check all of the brakes and they said they were all fine. Slick Spot was very professional and courteous but I am not sure how familiar they are with these brakes. Most importantly, they were quick to point out what they did not feel comfortable doing. Unfortunately, this also means that they cannot always tell you what they don’t know if what they are looking at is similar but not exactly the same of what they are used to seeing. I’ll call them later to see if they did any greasing.
While at Slick Spot, I talked with Jeff Rowe on the phone we discussed caging as an option but I then had the mechanic just readjust the brakes on the affected wheel but with a longer throw to engagement. I don’t know how much further apart the pads are over the standard dimension.
At this point, I am looking for a place to change the pads out and I’ll keep the rotor as is. I assume that the new pads will bed in to match some of the small irregularities of the rotor and since it is the tag, it is doing the least amount of braking of the bus anyway. If I am missing something with this thinking please let me know. The main reason for doing just the pads is that the shops seem to stock the pads but not the rotor. I’ll also point out the procedure for removing the excess grease to make sure.
I do remember Jon cautioning about over greasing the brakes in the seminar and on other occasions but there is only so much my brain can retain and I figure that is why I go to the experts.
Would a faulty slack adjuster be another potential source for the issue?
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Andy, automatic slack adjusters automatically adjust brake shoe/pad clearance.
When the calipers are greased using the proper procedure, the tech will know if they’re working properly.
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I understand that that is what slack adjusters are supposed to do when they are in good working order. Is it that rare that they never stick or be a concern for a point of failure? I just don’t know enough about them.
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I had a manual slack adjuster lock up on my tag about 3 years back. I pulled the Clovis pin and finished my trip. Your automatic may be different.
they do fail in a locked position, they are not on a timed schedule for replacement that I know about. I did change all 6 when I did my annual maintenance.
But as I mentioned above, it was clear what had happened. The smell and smoke was evident. It locked up for a couple miles and while I had a warm tire, I did not overheat and blow out the lube oil.
I think you would smell even a lightly dragging brake.
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A couple of years ago, I got a battery driven grease gun and in my exuberance over-greased one of the tag brakes as well. I noticed the very hot brake smell 20 miles down the road as I was filling up. Crept back home and put chocks on the wheels and lifted the tag wheel. It had freed itself by then. I’m now very careful about lubing the calipers.
After any maintenance, tire pressure adjustment or when starting out on a long trip, it is a good idea to stop after 20-30 miles and check for leaks, heat, anything amiss etc. This has saved my bacon a couple of times.
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Andy…BTW no slack adjusters when you have (SOME) styles of disk brakes.
For what it’s worth “cage off” the tag and go on your way. Use a heavy duty bar, screw driver to push brake pad back away from disc.
Find a plug for the air line, install a new hub cover, refill oil and your good to go.
That will eliminate the brake on tag, but you will be fine traveling.
Truckers and bus owners have been doing this for years… old timers like Bernie know this trick.
AL
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You DO HAVE SLACK ADJUSTERS on Meritor brakes which I think you have Andy. If you have Knorr-Bremse you have adjusters for the calipers built into the caliper.
If you have Meritor brakes it is probably the slack adjusters are automatic and they can fail, but the easiest way to verify everything is OK is to visually note the travel on the brake chamber rod pushing on the slack adjuster arm. Each axle has a specified acceptable range based on the brake chamber size, but with at least 90 PSI brake system pressure the travel should be around 1″ (not less) to 2″ (not more).
If the brake chamber pushrod shows a red ring where it comes out of the chamber the travel distance is unacceptable and the slack adjuster needs to be adjusted.
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They appear to be Knorr-Bremse to me, Jon.
I added the word “SOME”.
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