Front wheel removal of 1998 Prevost XL

[Gil_J]

Ben,

There are 2 different treadle valves and here is what Bendix states:

"The E-10™ dual brake valve (Figure 2) is similar to the E-6™dual brake valve except that a metal coil spring housed inan upper body assembly replaces the rubber spring used inthe E-6™ valve. The use of a metal coil spring (and the upperbody assembly) provides greater treadle travel and, therefore,provides the driver with a less sensitive "feel" whenmaking a brake application. The E-10™ dual brake valve isgenerally used on buses, where smooth brake applicationscontribute to passenger comfort."

So, the question is which one is suppose to be on your bus? I'll try to look that up later. Before I do, Joe probably has the answer.

[Joe Camper]

Ive never replaced one Gill. Every now and then air will leak out the exhaust port that is located on the bottom of the valve up on the ceiling of the steering bay that fools many and has people replacing them because of it. If u ever hear leaking from there its almost for sure one of the 3 R12 brake relay valves.

Your description of the E10 characteristics could explain both questions. First my thoughts on engagement of antilock on dry road. Maybe it can of u push that hard at speed. It would answer and also explain the soft pedal feel as well.

I've never had any truck or bus that needed this replaced.

[Ben Neumann]

Joe, it is the treadle valve and the new one is an E-10 like Gil is describing. The leak on the drive axle hub is on the inner seal. I took the big brake drum and seal to my local parts supplier for turning the drum. They are unable to do it locally and are shipping it to Sacramento, CA. I live about 50 Miles from Sac. half way between Sac. and South Lake Tahoe, CA.
Hope to get it back on Monday. The drum was very uneven and has hundreds of small heat cracks to the extent that I am worried it might be rejected for repair. The passenger side probably will look the same. When replacing the front bags I also noticed these fine cracks on the front rotors. I think I mentioned that I completely replaced the drivers tag axle brake rotor and brake pads. They were completely destroyed. I am hoping, when I get my brake drums back, that I will see an improvement. When you feel the inside of the drum, it feels very wavy inside. I also have to get new shoes for the one side because of the oil on the brake shoes.
The reason I am so concerned about the stoping power of this bus is, because I had an incident where I almost rear ended a young women in an TOYOTA . I was in Pomona,CA and was driving my Eagle Bus from one Freeway into the Hwy.10 headed for Palm Springs, CA. While trying to merge into the #10 from my on ramp I had the foot all away on the throttle and was looking over my left shoulder to merge. The traffic on the on ramp in front of me was moving freely and when I looked forward again, the traffic had competly stopped. I must have been going at approx. 45MPH and hit the brake as hard as possible. I got the bus to stop less then a foot from the TOYOTA. I ended with flat spots on all eight tires. If I had been in my Prevost at that time, I do not even want to think what the outcome would have been. I am alwys thinking about it and something tells me over and over again "my bus is not safe because of the brakes". I hope I never get in to a sitiuation like that again.
Ben

[Joe Camper]

I wouldnt turn a brake drum. Ever. I wouldnt buy brake components for prevo from anywhere than prevo. If u do not send the hub with the drum for turning there is the possibility it will run out when reattached to the hub.

If u do not like it replace it. When u turn a drum u have to use oversized brake linings. Don't like that either.

When u do the brake linings on prevo the linings and shoes and hardware, its all seporate. Lots of labor.

Im not saying u cant I'm saying experience has taught me different.

Small cracks in the brake drum r common, small cracks. Saturated linings can be dried out with brake parts cleaner with great results.

Did u index the bearing retaining nuts before u loosened them so u r sure it goes back togeather correctly?

I'm thinking your disc brakes r different on the steer and the tag. Correct?? I think your year is one that has the brakes on your 3 axles all configured different. Bremse front, drum drive, rockwell tag.

If u pull the front rotor it is knorr bremse unlike the tag that's rockwell. Be sure to locktight the mounting bolts for the caliper bracket on the front if u do.

There is a gasket that goes with the inner seal on the drive hub. Were those screws tight? That could have been the leak. Do u have the replacement gasket?

When reinstalling the axle be sure to tighten the studs with the cones first.

These vehicles r the safest things on the road but u cant drive them like a car. They r so smooth they lul u into a false sense of security. If u make that mistake it could cost u severely. Idiots who stop on freeway entrance ramps should have their lisence suspended, indefinitely.

[Joe Camper]

20140310_103529.jpg20140310_103635.jpg

This is the backside of a drive axle hub.

20140307_152119.jpg

Here is a shot of how the inner seal is designed on a prevo drive axle. This is different from truck stuff and most other hubs for that matter. On most the seal is pressed in directly to the hub. Prevo has chosen to add a another element with a flange and a gasket that is held in with Phillips screws that can come loose and make a leak. A common rookie mistake would be to reinstall the seal without first inserting the inner bearing. LOL

We have all done it.

[Ben Neumann]

Thank you Joe for your input. I have a different hub then the one you are showing on the pictures. I wished I knew how to post photos. Still something to learn for me. My hub does not have the small removable top peace like yours. It has a large encasing over the entire back part of the hub. I took a picture with my IPad. Also, when I removed the hub, I noticed, that the bearings had really been torqued down hard. I thought something like that should not have more then 50 foot pounds. It took some power to loosen it, but I do not know exactly how tight it was. I had no idea that it was important to know that. My old brake drums where made by Meritor and I am getting the exact same ones. I ordered them from my local parts house and will get them on Monday. I also ordered new brake shoes for both sides. These brake shoes are supposed to be a little bit different and I hope it will make a difference in braking power. At this time, I am thinking of removing the front wheels again and purchasing brand new brake rotors. Remember, I have a new rotor on my drivers side tag. I am also thinking of replacing the brake pads with the same type of lining I am getting on my drive axle.
I hope all of this will make the improvement I am hoping for. If it does't, I am really thinking of changing the front brake pods. I think they are #24 and replace them with 30th. This is just a thought at this time and I am not sure if it's even possible.
Currently I am stuck because I am out of parts and still need to replace the bags on the passenger side. The bag replacement on the drivers side is complete and it was an easy task. I will continue Tuesday, after I receive the new drums and brake pads.
Ben

[dale farley]

Ben,

This link will walk you through posting photos. If you have a problem, just let me know. http://forum.prevostownersgroup.com/...-Post-Tutorial