Front wheel removal of 1998 Prevost XL

[Joe Camper]

No slack adjusters????? Oh no Mr Bill how could it be?? Its magic!!

Just kidding. I'm a firm believer in these knor bremse brakes. Noticed lot of fire truck chassis also use them whatever that's worth.

Thats Great news.

OK I have resurrected a knore bremse brake thread that contains everything in regard to the brakes. It will explain the adjuster along with everything else. Go read through that.

I have someone checking the prevo service manuals for me so I can be absolutely sure the info regarding the pinch nut is spot on.

He has an extra prevo service manual for your vintage if u would like it he said 50 bucks that's a deal u should have it. He used to be a pogger, Lonesome George. Lemeno I'll hook u up and post the correct reassembly of the pinch nut and corresponding washer.

In the meantime read through the brake thread I've pulled up.

[Ben Neumann]

Thank you Joe, it will be great having the Manuel. When he is ready to ship, please have him email for payment and shipping address. berndgehrkeneumann@gmail.com. I am going to look for the article on the slack adjusters.
Ben

[Joe Camper]

OK Ben I checked with some friends and then put in a call to prevo to double check on torque spec for reassembly with knore bremse brakes.

This is good stuff so I hope there r others out there that can laugh at this stuff.

In the manual they refer to the six large bolts that hold the caliper bracket on "caliper set screws" LOL

In the manual they refer to the long caliper slide pin bolts "caliper bracket nut"

In the manual they refer to the pinch nut as "pinch bolt" LOL

In any event here r all the correct torque numbers

Pinch nut would be set 1\2 of 1\1000th to 2\1000ths from just touching snug. Its bolt that squeezes it 25 ft lb

The 6 large caliper bracket bolts 325 to 350 ft lb and the prevo tech assured me and convinced me to go to blue locktight it is a better solution to the red originally used. Those SOBs r so so hard to crack loose with the red on
them.........

The 2 long caliper slide pin bolts r 85 to 105 ft lb. They come with blue locktight already on them.

After me and lonesome couldn't bang our heads together on the definition and terms used in the manual I decided to call prevo to make sure and these numbers have been confirmed.

So the pinch nut thats no more than 2\1000ths here is what that means to a grease monkey. Let's go over that.

The rotor and hub is massive and heavy. Get it on a sturdy cart on a smooth surface and using 2 stacks of wood line it all up just outside the spindle. Take your time block it so it sits lined up without having to hold it and get it perfect to just a shim low if your off not higher. Then grease the inner bearing and the seal and the spindle. If the bus gods r helping u it will push up and far enough to put the washer up and thread up the punch nut.

2 things here that r figity and a fuss. first the washer needs to be physically centered as u run up the pinch nut to it. If u don't u will trap the washer between the nut and a flange in the spindle where the threads end. This is s very easy mistake to make and don't progress until u get a feel for that and u know its centered. Its a very slight lip and slight difference in feel between centered or not.

Secondly the pinch nut is round and u can't just put a socket on it when your reassembling like any other hub with a regular nut where u can ripp it very tight initially turning the hub before backing it off to the right spot to assure the hub is seated.

U can't do that easily with that round nut. So use rubber gloves and if u grab it real hard u can turn it down far and hard enough while turning the hub to get the hub totally bottomed out so when u back the pinch nut back to right at the point where its just touching or that magic spot. Then I'd turn the nut counter clockwise 1in at its outer diamiter and lock it down. Then that will set right and not change going forward.

Hub cap gasket oil. The 8mm caliper adjuster on the back of the caliper, after u put the linings in tighten the caliper till its clamped to the rotor and 1 click back. Put silicone on the clip retainer.

1 other thing is the abs sensor. Its adjustment can be changed if it gets bumped. In fact that's how u adjust the sensors by tapping them closer or further. U can very easily bump them without knowing it when pulling the massive hubs. After u put the hub up if u don't have the book be sure the wheel sensor on the side your Woking on is the same as the hub on the other side. Its moved with very slight blows with a punch and hammer.

[Ben Neumann]

Thank you Joe, just read your post after I tried this afternoon to reinstall the front wheel hub and rotor. I am exhausted and totally frustrated because I was unable to slide the hub on to the spindle. I even separated the rotor from the spindle and was able one time to slide just the hub by itself without the rotor on to the spindle. Apparently the tolerances between spindle and bearing are so tight, that the slightest disalignement binds the bearing on the spindle. At this time I am wondering if I should use a little bit of force and use a block of wood and a hammer to get the bearing on to the spindle. I am reluctant doing this and make a mistake by jamming the bearing on to the spindle.
At your post you are describing how to do it. I wished I had read your post first before I started. I used a large floor jack instead of the wood. I think I had it lined up pretty good and under normal condition it should have slipped right on. I never thought I would have a problem getting the hub back on, I thought the difficulty would have been to lift the caliper back on to the wheel and get the bolts back installed. Going to give it another try tomorrow morning.
Ben

[Ben Neumann]

Joe, today on Saturday I made my second attempt to install the hub and rotor. I got it done. What I did was take the rotor off the hub and lifted it on top of a floor jack and then adjusting it to to proper height on the spindle. I tied it with a wire to the upper a-arm to hold it. Then I cleaned the spindle and the inside of the bearing, removing any oil. Got the grease gun and covered the spindle and inside collar of bearing with all-purpose grease. Now I took the hub and it almost went effortless on to the spindle. Moved the rotor close to the hub and inserted and tightened all bolts. By keeping the rotor and hub separated, I was able to preform the task by myself. Installed the large washer and nut per you instructions. I think I got it right. I prepared the caliper for installation and cleaned and lubed the shafts. I did not have time to call for the repair kit as per your advise. Will do so in the spring time when it will be easier to work outside. This afternoon I will try to get the caliper installed. Need to make a jig on top of my floor jack to lift this monster. I think the hub by itself weighs close to 90 lbs. The rotor is about the same, but the caliper is approx.100 lbs. Just a guess. Will keep you up.
Ben

[Joe Camper]

Good job. U were fortunate to be able to separate the hub and rotor because the alen heads get so corroded u can't loosen them without stripping the head. If u put good silicone in the alen heads it will keep them from corroding further and u will get them apart next time too.

Be sure to check the gap on the wheel sensor for the antilock.

Be sure to refill the hub a second and third time waiting a few hours each time.

U could remove the brake chamber from the caliper with 2 nuts that would make it lighter a little.

U give me hope that I will be able to continue doing this about a decade longer than I thought that any reasonably healthy guy could.

That stuff is heavy but im not sure its that heavy LOL in any event U r amazing.

[Ben Neumann]

Joe I was worried you were froze in. I am watching the news about the cold in the Midwest and East. Even here in Northern California it is unusually cold. At my place (3100' high) it got down to 26 degree)
Yesterday afternoon I tried to install the caliper but failed to do so. Was just too heavy for me and I injured my right arm a few days ago. I lifted it with my floor jack as high as possible inside the wheel well and secured it with a rope to the upper a-arm. Had to wait for my son in law (who is a big guy) to move the unit from the jack over to the wheel. Will install the bolts this morning and using the blue lock tied as you suggested.
The bolts fastening the hub to the rotor on my bus are not allen screws. They used 22 mm hex bolts. Was easy to get them off. I got my new 3/4" impact. Can't believe the power it has and it is a light weight unit. Thanks for the advice how to lube the wheel. I will go back this morning and finish this wheel and hope to start disassembling the passenger side wheel. I again will not have any time to continue working the project before Thursday or Friday. Will keep you up.
Ben

[Joe Camper]

As different and as figity and physical all this is, compared to ......, If there is any 1 thing that needs stress is getting the pinch nut set perfect.

When u do the other side before loosening Index that slot in the nut and count the exposed threads and be sure what the backside of the washer is. I'll feel a lot better if u promise.

Look at the gap for the antilock sensor beforehand in case u bump it.

Back the caliper out all the way before u pull it out. Count the clicks and see how much pad u have used and have left.

It is a beautiful sunny day in Chicago. Current weather is a 10 mph wind, 9 degree noon time temp dropping to 10 below for an overnight low.

[Ben Neumann]

Followed your instructions and also took a close-up pictures of the pinch nut. Counted the revolutions it took to get the nut off. There was a center punch mark on the spindle and it took exactly 10 1/2 turns to get the nut off. I got as far as dropping the caliper to the floor. I again tied a rope over the upper a-arm and lowered it down. My new 3/4" impact gun preformed fantastic. It is an "Air Cat" and has 1400 foot pounds of tork and is light weight. I am surprised that such a lightweight gun can produce such a brutal force. I think I paid $290.00 at amazon. It ripped those large bolts loose in the lowest power setting. What a difference when you have done the job once before. Did not have to experiment any more. Took more pictures and wrote myself some notes. Hopefully I will continue my work on the bus on Thursday. Need to get back to work repairing my daughters and her husbands new house. It is a fixer-upper.
Ben

[Ben Neumann]

Joe, a few days ago I contacted George and purchased the repair Manual. Nice fellow and very knowledgeable about the Prevost Bus.
Yesterday afternoon I finally had time to finish my work assembling the wheel and brake assembly. It sure makes a difference if you have done it once before. Took me no time to get the job done. This time I lubed the spindle and the inside of the wheel bearing of the hub with some moly grease. Worked great and the hub went on effortlessly. Will finish up installing the oil hub and filling it with oil. Also need to go back to the rear and fill the drive axle with oil. It will be exciting taking the bus on a test drive to test the brakes. I hope the work I did will lead to a major improvement to the overall braking capacity. I was asking George if he knew if there are any pressure regulating valves between the E10 foot valve and the wheels. In other words,"if you step on the brake is there any air pressure reduction between any of the wheel brake chambers and the E10? He said he did not know but also said he did not think there was. I would like to ask the same question to you.
Ben