Jakes, Automatic Downshifting and New Brake Shoes

[Glennman]

Ok, as I mentioned in another thread regarding my Jakes, we attempted to wire them direct which didn't work. In the meantime, we drove the bus to the beach last weekend, and now the transmission no longer automatically downshifts to 4th gear at foot braking like it used to. To top it off, I ended up having to come to a complete stop on the westerly downhill side of White Pass (6 percent grade). Now my new brake shoes are glazed, they squeal really loud and they stunk too.

In researching the brake lining material, apparently there is a material that transit authorities use called "KVT" because (as they say) they are less prone to glazing and would work well on mountain grades. Typically, when descending a grade, I use short, stiff brake applications, but since I was forced to come to a stop, I had no choice but to do just that. Now my 500 mile shoes are messed up.

I know there are a lot of subjects here, but they are kind of intertwined. Has anyone ever heard of KVT shoe material and any suggestions on the automatic downshifting would be much appreciated.

[luvrbus]

KTV linings are non metallic ( no copper)a soft lining school buses use that type lining too. I installed new pads on my Lexus made by Nairobi the same type material.
 The B500 should not down shift to 4th gear without the Jakes switch turn on. You have a commutations problem could be a bad harness, a bent pin something simple or a bad ECM.A DD-Allision dealer has the equipment to check that for you. If you want to keep fighting it I have both the application manuals for the B500 and the series 60,I will let you use, they are rare and hard to find I would want those back, I have nothing on the MCI chassis modules. Testing the system has to be broken down in 2 parts, the OEM reasonability stops at the ECMs , the manufactures reasonability goes from there. That bus should have the ABS system the Jakes could be programed to work with the ABS system from MCI if it was down shifting by applying the brakes       
 

[Glennman]

KTV linings are non metallic ( no copper)a soft lining school buses use that type lining too. I installed new pads on my Lexus made by Nairobi the same type material.
 The B500 should not down shift to 4th gear without the Jakes switch turn on. You have a commutations problem could be a bad harness, a bent pin something simple or a bad ECM.A DD-Allision dealer has the equipment to check that for you. If you want to keep fighting it I have both the application manuals for the B500 and the series 60,I will let you use, they are rare and hard to find I would want those back, I have nothing on the MCI chassis modules. Testing the system has to be broken down in 2 parts, the OEM reasonability stops at the ECMs , the manufactures reasonability goes from there. That bus should have the ABS system the Jakes could be programed to work with the ABS system from MCI if it was down shifting by applying the brakes       
 
Thanks luvrbus. I appreciate the offer. The trouble is that I would probably only get more confused if I had the manuals in my hand. If I decide to go that route, I'll certainly let you know. I'll get a hold of my mechanic and see what he thinks.

I'll be ordering the new KVT lined shoes and give up my old ones with 500 miles on them as a core. It's unfortunate, but it's not like they sold me the wrong ones. They say that it's expensive to obtain a quality education these days.

[buswarrior]

I absolutely despised that MCI forced downshift to 4th along with Jake or retarder application.
No way to make it all work without rough operation to the passengers and often, too much slowing for the situation.
The period correct Prevost did NOT behave like this,driver decided what to deploy and in what measure.
Imagine just dragging the jakes a little in 6th gear... lovely fine control.

Amongst your problems, I'd be getting that programming all cancelled out.

What makes you think anything is wrong with your pads after one stop? They all make noises out in the revenue service world?

happy coaching!
buswarrior

[Glennman]

I absolutely despised that MCI forced downshift to 4th along with Jake or retarder application.
No way to make it all work without rough operation to the passengers and often, too much slowing for the situation.
The period correct Prevost did NOT behave like this,driver decided what to deploy and in what measure.
Imagine just dragging the jakes a little in 6th gear... lovely fine control.

Amongst your problems, I'd be getting that programming all cancelled out.

What makes you think anything is wrong with your pads after one stop? They all make noises out in the revenue service world?

I've gotten accustomed to the automatic downshifting. When flying down the Oregon coast, the braking on the curves with the auto downshift only seems completely natural. Since the bus has never had functioning Jakes nor a retarder, then it's not like the downshifting was added to those, since they never existed. So now, I have no Jakes, no retarder and now no downshifting.

On the new brake shoes, one trip over the mountains and now I'm getting noise like I've never had, chatter when braking, especially when braking on a downhill curve, you can feel it grabbing and letting go (chattering) when going around the curve. I pulled the drums (also new), and the shoes are literally as smooth as glass and cooked.

In speaking with people at Six Roblees, they have the KVT shoes especially for transit authorities that are apparently supposed to alleviate these kinds of problems. I'm going to be picking up a set, as we're heading down to southern Utah next month, so I want to have the brakes in tip top shape. Thanks.

[luvrbus]

It not just MCI the Allision WT all down shift to 4th with Jakes from the factory the B500 is bus transmission only but are the same as all the 4000 series it  is a default setting that has to be changed to stop the 4th gear drop. If it was downing shifting it has to be getting a signal from the Jakes or the brake system.My Allision 4060 would down shift to 4th before I had it reprogramed, The World trans will not downshift without reading the RPM of the engine setting of 2100 rpm to prevent over speed of the engine. My ISX Cummins would use the turbo for braking till the 4060 read where it was in the safe zone to engage the Jakes. It's new school the Allison controls the engine and tells it what it wants. I think you have a Clarke Power in your area bite the bullet and take it there if you want Jakes, you are wasting time and money using a independent shop 

[Glennman]

It not just MCI the Allision WT all down shift to 4th with Jakes from the factory the B500 is bus transmission only but are the same as all the 4000 series it  is a default setting that has to be changed to stop the 4th gear drop. If it was downing shifting it has to be getting a signal from the Jakes or the brake system.My Allision 4060 would down shift to 4th before I had it reprogramed, The World trans will not downshift without reading the RPM of the engine setting of 2100 rpm to prevent over speed of the engine. My ISX Cummins would use the turbo for braking till the 4060 read where it was in the safe zone to engage the Jakes. It's new school the Allison controls the engine and tells it what it wants. I think you have a Clarke Power in your area bite the bullet and take it there if you want Jakes, you are wasting time and money using a independent shop 

I googled Clarke Power and the closest one is Missouri. I'm in Washington. I'm thinking of at least calling them and discussing it with them. We have family in Missouri where we've driven the bus to before. I wouldn't be afraid to make a trip there if I thought it would get me some Jakes.

[luvrbus]

I googled Clarke Power and the closest one is Missouri. I'm in Washington. I'm thinking of at least calling them and discussing it with them. We have family in Missouri where we've driven the bus to before. I wouldn't be afraid to make a trip there if I thought it would get me some Jakes.

It doesn't have to be Ckarke Power any DD & Allision dealer can solve your problem ,I have had good luck with Smith's in Boise Id,I wasn't too happy with Tacoma Diesel the 1 time I used it,but it was 20 years ago on an 8v92 Detroit. It is too bad WW Williams dropped their parts and service on MCI buses, it made life easier for MCI owners. Williams now owns all the Valley Power locations I look for those to servicing buses before long,Valley had a location in WA or OR state