International S1954 hydraulic brake help

[deezlugnutz]

I have a little single axle 1982 International S1954 dump truck that I'm working on with hydraulic brakes with a DT466 and a hydroboost setup with drum brakes all around. On the first brake application the pedal is somewhat spongy and travels further than usual, however the truck still stops fine. If you quickly let up on the pedal and do another brake application, the travel of the pedal is normal and it still stops great. However if you release the brake pedal for a few moments and then apply it again, the first application is spongy again.

I feel like there is air trapped in the system somewhere, however I have bled the system a lot and still have the same issue. The original master cylinder was weeping some, and I couldn't find a replacement anywhere. I noticed that the whole hydroboost system looked very similar to what is on a GMC C6500 parts truck that we have. The master cylinder fit perfectly although I had to change the flare fittings and reflare the lines on the m/c side. Works great but the spongy pedal issue persists. Worth noting this problem existed even before I replaced the master cylinder.

The brake setup on this truck uses two wheel cylinders at each wheel - on the front end there is a cylinder on the front and the rear, and on the rear axle there is a cylinder on the top and bottom.

I pulled off one of the front wheels to have a look as there was no adjuster I could see from the rear. Shoes look good and no evidence of leaking wheel cylinders at any of the four corners. I'm not exactly sure how the self-adjustment works on these, it appears that there is a rod that sticks through the shoes that must have something to do with it? I noticed one of the little springs on the bottom is hanging loose and the wedge piece is in a different location than the upper shoe. Doubt this is what is causing my pedal issue but worth mentioning nonetheless.

So, any recommendations on what steps to take for my spongy pedal? Just more bleeding?

Thanks for any help.

 

[Truck Shop]

Backside of backing plate there should be a hex head adjuster bolt, those are cam adjusted IIRC.
When bleeding always start at the right rear then left then right front then left. If spongy there's
a few bubbles in the system, bleed booster first. Plus using a pressure bleeder works best.
*
The lining on those shoes is getting down.

 

[MG84]

Your pedal problems are most likely one or all of the drum brakes are out of adjustment. You push the pedal the first time and it brings the brake shoes into the drums, but you aren’t getting full pressure on them until you give it a second rapid pump to really seat them. Once you let off the pedal for a few seconds the shoes retract and then you're back to square one. Sometimes air in the lines can feel similar, but my money is on the shoes being worn/out of adjustment.

Those front brakes in the pics are Bendix dual cylinder, single piston brakes. I have the same brakes on the front of a 1980 Ford f600. They are “self-adjusting”, but only when everything is clean, straight and working properly, IE they probably aren't doing any self adjusting. As Truck Shop said, there is a hex head bolt on the back of the backing plate you can turn to manually bring the shoes closer to the drums. Most likely they are seized up too. Best course of action is to disassemble, clean, repair/replace any parts that need be and maybe some new shoes. Most all of these hyd brake parts are not make specific, Ford, GM, IH often used the same parts. NAPA should have everything you need, shoes, hardware kit, etc

 

[Truck Shop]

Sometimes air in the lines can feel similar, but my money is on the shoes being worn/out of adjustment.

Correct-first step is adjusting brakes.

 

[deezlugnutz]

Backside of backing plate there should be a hex head adjuster bolt, those are cam adjusted IIRC.
When bleeding always start at the right rear then left then right front then left. If spongy there's
a few bubbles in the system, bleed booster first. Plus using a pressure bleeder works best.
*
The lining on those shoes is getting down.

Your pedal problems are most likely one or all of the drum brakes are out of adjustment. You push the pedal the first time and it brings the brake shoes into the drums, but you aren’t getting full pressure on them until you give it a second rapid pump to really seat them. Once you let off the pedal for a few seconds the shoes retract and then you're back to square one. Sometimes air in the lines can feel similar, but my money is on the shoes being worn/out of adjustment.

Those front brakes in the pics are Bendix dual cylinder, single piston brakes. I have the same brakes on the front of a 1980 Ford f600. They are “self-adjusting”, but only when everything is clean, straight and working properly, IE they probably aren't doing any self adjusting. As Truck Shop said, there is a hex head bolt on the back of the backing plate you can turn to manually bring the shoes closer to the drums. Most likely they are seized up too. Best course of action is to disassemble, clean, repair/replace any parts that need be and maybe some new shoes. Most all of these hyd brake parts are not make specific, Ford, GM, IH often used the same parts. NAPA should have everything you need, shoes, hardware kit, etc

Correct-first step is adjusting brakes.

Thanks so much yall for the information. Huge help. The rear has the traditional "star" adjusters, one for each shoe, which as you all mentioned were pretty seized up. A little working at them and I got all four of them loose and adjusted, they were way out of adjustment.

I'm off to NAPA to pick up wheel seals for the front end and I'll see about getting new shoes and hardware kits for the front end. I'm 99% sure this is my problem - one of the cam bolts is completely missing on the right front, and the lower one when I rotate it will turn 360* and roll over like the s-cam on a wore out air brake system. I'll have to pull that side apart and see what's going on. Hopefully the cam bolt and spring aren't hard to find??

Thanks again for the help, nice to see some knowledge still available about these old trucks - searching around on google brings up very little info.

 

[MG84]

The hex head adjusting bolts we mentioned will turn 360* and they are basically just a cam shape on the back. Sometimes it's a bit fiddly to turn them the right direction and far enough, without going too far (over the back side of the cam shape). Napa will have the shoes, hardware/spring kit, and the self adjuster hardware that goes inside the brake shoe, but probably will not have any of the hard parts for the backing plates. O'reillys also has many of these medium duty parts, but you better find an old guy behind the counter that will get out the paper books, their computer system is poor at best when it comes to this old stuff. NAPA is about the same acutally, the biggest battle is just finding a part #.

 

[MG84]

Also another thing, if the brake hydraulics (wheel cyl, etc) are working fine, don't mess with them. The 40yr old, mostly worn out, made in USA stuff that's on there is better than the new crap parts from China. That's my biggest battle keeping these old trucks running is the pi$$ poor replacement parts that are available.

 

[deezlugnutz]

The hex head adjusting bolts we mentioned will turn 360* and they are basically just a cam shape on the back. Sometimes it's a bit fiddly to turn them the right direction and far enough, without going too far (over the back side of the cam shape). Napa will have the shoes, hardware/spring kit, and the self adjuster hardware that goes inside the brake shoe, but probably will not have any of the hard parts for the backing plates. O'reillys also has many of these medium duty parts, but you better find an old guy behind the counter that will get out the paper books, their computer system is poor at best when it comes to this old stuff. NAPA is about the same acutally, the biggest battle is just finding a part #.

My parts guy at NAPA is normally great at tracking down parts for older stuff for me, but between me and him we cannot seem to find the right shoes to fit this truck. The current shoes are 15"x3.5". Cannot seem to find any that fit. We did find the hardware kits, NAPA 80882 and 80881 (left and right front), match perfectly what is on the truck now. Whether or not they are assembled correctly, I'm not sure.

Starting to wonder if this isn't the original front axle this truck was built with? Any idea on parts numbers for the 15x3.5 shoes? No numbers on the shoes at all.

I also need to find part numbers to use for the missing cam bolt and spring.

The hydraulics seem to be working fine. No leaks. The GM master cylinder I swapped on seems to work fine as well. Wish I could just move the whole front axle off the 6500 over, (it has disc front brakes), but the springs are different widths with around 3" on the International and 3.5" on the 6500.

 

[deezlugnutz]

After scouring every corner of the internet I finally found this Meritor PDF which matches what I think is the shoe...

https://graphicvillage.org/meritor/TP12162.pdf

The R700463 looks like it's the one. According to that Wagner was who originally manufactured them I think?

As for finding a couple sets of them... I might be SOL. Not looking good!

 

[deezlugnutz]

These look basically the same, but 3". Wonder how well those would work in place of the 3.5" shoes.

https://www.napaonline.com/en/p/UP_UP321HR

 

[Truck Shop]

You may have have your old shoe webs relined, there are places that still do that.

 

[Truck Shop]

These look basically the same, but 3". Wonder how well those would work in place of the 3.5" shoes.

https://www.napaonline.com/en/p/UP_UP321HR

You could do that, but because your talking about brakes--I won't say it's OK.

 

[deezlugnutz]

You could do that, but because your taking about brakes--I won't say it's OK.

I agree, definitely not ideal. Getting them relined is a good idea. Any idea what the correct way to assemble the hardware on these is? I put them back together the way they came off. Don't think they were put together right the previous time.

 

[Truck Shop]

https://www.showmetheparts.com/raybestosbrake-parts/raybestosbrake-322pg.html

 

[deezlugnutz]

https://www.showmetheparts.com/raybestosbrake-parts/raybestosbrake-322pg.html

Thanks, looked through where that site took me and everything looks out of stock as well. Might try that number at my local NAPA and see if it gets me anywhere though.

Still can't make any sense of how the hardware kit is supposed to be installed correctly. Maybe it's just not the right parts for this truck. Seems whatever brakes were in use on this one are pretty much completely discontinued from any aftermarket today.

Would be great if I could find a front axle with more common parts that I could swap in. Looks like everything is still readily available for the rear. I may do some more measuring on the GMC 6500 axle and see if the center to center distance is the same between the leafs on each side, guessing it might be possible if I could find the right pieces to lock the 3" springs in place between the 3.5" spacing on the GM axle. Looks like I would just need something to keep it shifting side to side.

 

[deezlugnutz]

From that site you linked I searched some of the other compatable vehicles. 1980 GMC C6000 appears to have used the same shoes as what this truck has - https://www.napaonline.com/en/p/FLTFT322HR?impressionRank=2

Looks out of stock everywhere from NAPA, but I'll give the # to my guy and see what he can find. 15x3.5 looks like the right size.

 

[Truck Shop]

About 7 years ago I did some work on a early 80's 1954 the airport here has. Bad kingpins-
No kingpins for that axle were available. I luckily found a complete steer axle with good pins,
shoes. The shoes for it were obsolete also. I don't remember the hardware layout though.

 

[deezlugnutz]

About 7 years ago I did some work on a early 80's 1954 the airport here has. Bad kingpins-
No kingpins for that axle were available. I luckily found a complete steer axle with good pins,
shoes. The shoes for it were obsolete also. I don't remember the hardware layout though.

Yeah at least the front left kingpin is showing some wear on this truck. Not terrible but not great by any means either. Haven't had the other side jacked up yet to see how it looks. Knowing now that kingpins will probably be near impossible to find it looks like swapping in another front axle may be the way to go. Disk brakes would be nice too. We've got some other newer (comparatively) internationals on the lot, I'll take a look at the 4700s and see if dimensionally those might be better fit. Finding one of those shouldn't be hard with as many 4700s are out there.

 

[deezlugnutz]

So here's the conclusion I've come to - I found an old Bendix PDF (I've attached it) that has full breakdowns of the parts. What appears to be going on is the shoes and hardware kit that are on this truck are not the correct ones for the truck.

Previous owner(s) have used 1280-322 shoes and the H9237 hardware kit which is for the trucks that had automatically adjusting brakes.

After comparing the backing plate designs, I believe this truck did not have self-adjusting brakes originally, and instead needs the 1280-463 shoes and a different hardware kit and adjuster cam. Explains why I couldn't figure out for the life of me how the self-adjusting mechanism was supposed to work. The cam bolts themselves appear to be the same.

I was able to find the adjuster kits on eBay after finding that they cross to a Euclid E-4131 which crossed to another aftermarket part that includes everything but the spring and cam bolt. I also found a cam bolt to replace the one I am missing. The only piece I cannot find is the spring. I'll see what I can come up with for that.

Neither of the shoes (the correct, or the current shoes that are on the truck) appear to be available anywhere, so getting the relined appears to be my only option. However, these still have some life in them so I'll cross that bridge when I get there.

The good news is that the shoes and self-adjusting hardware I have on the truck now seems to work fine for manually adjusting. Functionally I don't think there will be any difference in how the manual/auto hardware kits adjust the brakes when it comes to turning the adjuster cam bolt by hand.

Waiting on the parts to do the passenger side front, got the drivers side done, new wheel seal, and back together.

I noticed the rear axle was not centered, so I got the u-bolts loosened and shifted the rear axle over to where it's sitting nice and even now and got all that back together.

Hope some of the information here might help someone else with an older truck like this.

Next I need to find some engine mount insulators for the rear engine mounts- the ones on there now are totally shot. Shoulda done them when I did the clutch (it has a Spicer 5-speed with a dual disk that was worn out), but didn't have time to track down the parts.

 

[walkerv]

Check fleetpride also they are nation wide , if no luck there then have to reline them