Hot Brakes

[doodlebug45]

We got in to a very twisty, mountainous chunk of road and I overheated my brakes. When I was finally able to pull over they were smoking and then I got oil running down the front tires. I haven't taken a close look yet but I presume I have damaged (melted) the plastic oil cups on my IFS front end. Any advice or words of wisdom would be much appreciated.

[Joe Cannarozzi]

I'd say your pretty lucky.

Was just the steer axle smoking? If so the brakes are adjusted incorrectly, or possibly the last brake job did not include all axles or also, auto slack adjusters do fail. Just to name a few. All axles should be grabbing equally.

I know that only some types of the automatic slack adjusters are adjustable and that is a perfect example why some do not care for them. There are choices, some auto slacks CAN be adjusted to ratchet sooner or later to fine tune for certain axles that mat be lighter or heavier.

I would not go another foot without a thorough brake and hub inspection.

I might suggest a slight change in your driving technique too. Begin your decent WAY SLOWER and keep it WAY SLOWER ALL THE WAY DOWN. If it is 2 lane and traffic is mounting behind you, so be it.

Where was this oil, on the outside or inside sidewalls? I would assume because of the heat all of your hub seals on any of the smoking hubs are subject to future failure. Wheel bearings too.

After you stopped those brakes/hubs actually continued to get hotter before they then began to cool down. I have come up on trucks and cautioned drivers about glowing brake linings who have pulled over and only after stopping experienced a flame up.

Thank God you got stopped and had no fire.

Ya know how some folks do not subscribe to this new technology like wireless tire pressure sensors because for one you then stop doing visual inspections that still need doing. Or outboard brake drums because hub bearings often go way too long without inspections because of that convenience?

Well because most now have automatic slack adjusters many no longer ever do thorough enough brake inspections like visually checking slack at every hub.

Could very possibly be that you had none of these mechanical shortfalls and you were just traveling too quickly for conditions. However, now the damage is done.

[flyu2there]

We got in to a very twisty, mountainous chunk of road and I overheated my brakes. When I was finally able to pull over they were smoking and then I got oil running down the front tires. I haven't taken a close look yet but I presume I have damaged (melted) the plastic oil cups on my IFS front end. Any advice or words of wisdom would be much appreciated.

Hugh,

You might want to head back to Desert West. You say oil running down on the "tires" by that I presume both fronts? The cups that hold the gear oil for the front wheel bearings, to melt them you must have really cooked the brakes which means possibly warped or cracked rotor (s), glazed over disc pads and possibly front wheel bearings.

Did you use lower gears and the jake on HI? I have been down my share of mountain roads, including Wolf Creek Pass, and rarely have to use my service brakes at all....use the Jake!

John

[Jon Wehrenberg]

Hugh,

Good previous advice. Here's my spin on this that nobody mentioned. Your excessive use of brakes due to driving technique may have contributed, in which case learning and using the correct procedures will eliminate the problem in the future.

But this may not have anything at all related to the driving techniques. On some coaches with disc brakes over greasing the caliper actuating shaft may prevent the pads from retracting after the brakes have been released and when that happens your brakes will overheat.

Not all front axle brakes however have a provision for greasing (nor do they need any) so that might not be the cause. What is important is to determine why they overheated, and to correct any damage that might have occured due to overheating.

I would have the discs checked for cracking or warping. I would have the pads checked. I would make certain the hub seals are not leaking. They are plastic and easily heat damaged. I would check the plastic hub cover to make sure it is not leaking. I would inspect the bearings to make sure they suffered no heat damage. I would make sure the wheels are flat where they bolt to the hub and were not affected by heat.

If this is solely related to one side of the coach my suspicion is that Joe is right about a possible faulty automatic slack adjuster. If both sides of the coach were equally hot, I would surmise the problem was driver technique and over use of the brakes.

BTW, this mention of driver technique is not a slam on you, but a message to all owners that driving in mountainous or hilly country requires techniques none of us would even think about in our cars, and that because these buses are in many ways as easy to drive as our cars we easily forget we do need to be more active in managing the energy.

[doodlebug45]

Thanks for the comments. I have now taken the hub covers off and had a better look. The wheel seals are definitely blown. There was no oil leaking until after I stopped so the comment about getting hotter then is probably correct.
I am pretty sure that the problem here was driving technique along with load. My toad is fairly heavy and even though I have a Brake Buddy, it was probably not set high enough. For the conditions we are in right now, I think the best solution will be to disconnect and drive the truck.
The big problem I have right now is that I need to replace the front wheel seals in place before I can go anywhere. I am currently in Mexico, in a little mountain village on highway 200 about half way between Tepic and Puerto Vallarta. The problem road was the piece I drove from Tepic to where I am now so I don't particularly want to go back that way.
I have the tools to do most any kind of work. I am about 80 miles from PV but suspect that translates into about 3 hours of driving. Any thought on this situation would be most welcome.

[Joe Cannarozzi]

So the oil that was leaking was coming down on the inside sidewall and the only axle that was smoking was the steer?

I have learned that when you heat things up coming down a grade and you know it but have made it to the bottom if you think you can cautiously continue for a little further instead of immediately stopping the time and air blowing through things cools things down considerably possibly preventing a fire or meltdown of the seals and more severe damage of other related components.

I see 2 choices 1-wait there for parts
2- if after further thorough inspection you have good braking
ability fill the hubs back up and proceed cautiously
checking the hubs frequently.

How much further you have to go to service the severity of the terrain and the severity of the leak are the factors that need to be considered to give you your solution.

If you proceed you know will have a mess on your hands with the seals leaking but that may be a compromise you will be willing to make.

When you are rolling centrifugal force takes that oil and pushes it out to the outer edge of that cavity engulfing the rollers of the bearings and when you stop is when it will settle to the bottom getting above the lip of the seal and probably leaking the most. Not a very reassuring thought or preferable situation but something to keep in mind.

If I were confident of my brakes the grades were minimal and the leak slight I would go the 80 miles.

[Darl-Wilson]

Hugh, I know the area very well and have driven that road lots of times. I have a 2 brother-in-laws that live nearby in Las Palmas and in el Ranchito Jalicso, near PV. They are a little more than an hour from you. Both are bus mechanics and one has owned buses for several years. I think many of the parts are generic. I know they have Eaton parts there along with about everything else. There is only one problem, THEY DO NOT SPEAK ENGLISH. But trust me, they DO know buses and are great mechanics. If you want to call or email me and we will call them. They are not expensive and will not take advantage of your situation. You will just need to have someone to interpret.

There are also some shade-tree mechanics around Las Varas and Rincon de Guayabitos Nayarit. They are on the west side of the Hwy 200.

My home phone is 775-852-1475 and email is darl@darlw.com. We can call you back with a calling card. Calls from there are very expensive.

Let me know.

Darl