The Stovebolt Site Forums The Parking Lot Big Bolts 2 1/2 ton brakes

I am currently working on my 2 1/2 ton chevys brakes trying to get them to stop leaking. They are FR-3 type brakes and one of the brass blocks that splits the line between the two wheel cylinders on the passenger side is cracked. Does anyone know of a place I could get a new one? I havnt been able to find one online and most of the trucks at the junkyard were air brakes.
Is there a trick to making the tapered dowels not stick in the axle flange for next time I have to get to the brakes? I had a hard time getting one of the studs back in and im not sure its coming back out.

MattMck,

Is your wheel bolt pattern 6 on 8.750 or 5/10 on 7.250? Is that broken block in the rear or front?

Ed

They are cast wheels so i guess that would be 5 on 7.250? Its the block in the rear.

Do you mean Daytons?

Ed

Yes, they are Daytons.

Matt, Is this what you need?

https://www.powerbrake-drivetrain.com/master-wheel-cylinders-wagner-fittings-fc1241-fc2579/

Mike B

Almost, but the one i need has two ports as well as the big hole which are at 90deg to each other.

Can you post a picture of exactly where this fitting is located on your truck. Is it on the front or rear axle?

Mike B

Will this work?

https://www.powerbrake-drivetrain.com/master-wheel-cylinders-wagner-fittings-f5727/

Mike B

It is the rear axle. That might work, but i think it would be tight around the bleeder valve. That or i would have to route the brake lines different. The old one is like that one but 90 deg between the ports. $70 is a lot for that little thing too

If you measure your kingpins, axle thickness, etc., front hubs/spindles off a modern truck might work, even might find with same bolt pattern. Matching rear axle night have higher gears also!

Ed

Im not sure replacing all the axles is the easiest fix for a small splitter being broken...

How about this one? Link It doesn't specify the port sizes, but would be worth calling them. You could easily cut the corner out to clear the bleeder.

If you do a internet search for 'Banjo Fittings Two Port' lots come up...you'll need to know your center hole and port brake line sizes.

Sad, I just junked a 1957 8400 chassis right before Christmas that had an Eaton rear under it that would have had those fittings on it...

Mike B

Could you have a tee that is remote from the wheel cylinder? Just plumb the tee mounted on the axle and run separate lines. A normal inverted flare tee could then be used.

MattMcK Just for information on your hunt they call that a banjo fitting,you can kind of see why with those cicles on there.

Thanks, the few im finding online seem like they are from the same company and have 7/16 ports instead of 3/8. Got a guy looking around some places he knows but nothing yet. Who knew a little splitter would be so hard to find.
I do have the piece that broke off mine. Maybe someone could braze it? Seeming like it would be easier to convert to air brakes than find this stupid piece! I could get all the parts from the local junkyard.

Is the purpose of the fitting to split the fluid from one wheel to the other? Why can't you mount a conventional inverted flair tee on the axle, run the main line to it and branch lines to each wheel.

It's to split the line to the TWO cylinders on one wheel. Reread the first post in the thread.

OK, got it now. OP might still be able to modify the set-up with a divorced tee. On my 2 ton rears, the line between the 2 cylinders is internal to the drum. I know he won't be able to do that but may be able to rig something other than the original parts.

That might end up being what i have to do at least temporary. Find a single banjo to fit and get a splitter remotely. Everything this big seems to have air brakes or that internal split in the bottom cylinder like you have 78buckshot.

So i made my own tee, and then discovered my bottom cylinder was leaking so i got a new one, however the thread size is 7/16-24 for the bleeder screw and where the banjo bolt would go (which is 7/16-20). I am thinking maybe I will just take out the bleeder screw and have that go to the other cylinder to bypass the T. That would essentially make it like the internal T cylinders and only bleed from the upper cylinder. Anyone see a problem with that? Ill just have to redo the brake lines going to it.

Finally found the right cylinder. Its dorman part W19107 and I found it on Walmarts website of all places.

Finally getting back to the brakes on this thing. I adjusted the brakes all the way tight on the wheels and pumped up the brakes. Then I unscrewed the cap on the brake reservoir to see if anything happened and when i started to let off the brakes, fluid shot up about a foot out. I didnt think that would happen if the brakes were tight. Could something be up with my rebuilt hydrovac?

The brake fluid was under pressure with your foot on the pedal, when you let off the pedal the pressurized fluid is released back into the reservoir making a fountain...that's normal.

Mike B

In that case, why the heck cant i get my pedal to be firm without pumping like crazy? Ive gone through a few bottles of brake fluid trying to bleed the stupid things. Are there any types of pressure bleeders that would be compatible? I want this thing driving so the guys at work will stop asking when I'm bringing it in!

MattMcK, this is how I did my brakes. My '57 2 ton is still the stock brake system, I rebuilt all 6 wheel cylinders and the master cylinder, I replace every steel and rubber line except the cross-over lines inside the rear drums. When I plumbed the new lines I hydraulically by-passed the frame mounted Hydro-Vac knowing that it needed attention. So I had a complete manual system with no leaks. I raised each wheel off the ground and adjusted the shoes so I had trouble spinning the wheel, rotated the wheel backward and forward to help center the shoes, readjusted as needed to have them scuffing the drums. I had a helper at the brake peddle as I cracked each bleeder, longest line first to the shortest last, with the wheels off the ground I could then try to spin each wheel, if there was no brake drag I re-adjusted for light scuffing, after driving a few short test trips I re-bled in the same order. The truck had a very high firm peddle and no leaks, I used it with manual brakes until I re-built the Hydro-Vac. After mounting the Hydro-Vac I re-connected the lines as original and gravity bled the hydro- Vac, the system is working real well.

Are you following the service manual instructions on bleeding the brake system?

Mike B

I have replaced or rebuilt all the cylinders that were leaking, had the hydrovac rebuilt, new master cylinder that came with the truck. I didnt replace any rubber lines since it was a firetruck and they looked fine. Besides using a pressure bleeder like the manual says, i followed those instructions for bleeding. Adjust for drag, farthest bleeder-in. If the master isnt quite big enough bore would that do it? I never checked the bore, just assumed it was right.
Never had trouble bleeding brakes, this is frustrating me XD

I bled my 2 ton with a home-made pressure bleeder, ended up doing it a 2nd time, before I got a good brake pedal. What bore is the master cylinder that came with the truck? On my 2 ton, the outside of the master looks like the same one that was on my 1//2 ton Suburban.

Not sure what the new one is, I was just told its a new one for the truck. Probably should have taken the time to pull it apart and measure i guess. Might be my next move.

Your Master Cylinder should have a bore of 1.5".

Brake lines rubber and steel fail from the inside out, they might look good on the outside but are one push away from failing from the inside.

Did you bench bleed the Master Cylinder?

Did you bleed the Hydrovac's two bleeders first before going to the wheels following the service manual instructions (1955 book)?

Mike B

Bled the hydrovac like the book says, didnt bench bleed the master tho. Just fill it up and screw the cap on then tip it so the outlet is up and pump it?

Next step might be tracking down the original master cylinder since im pretty sure I cant buy one right? And cant bore out a 1.25"? While im at that ill replace all the lines i havnt already.
Anyone happen to have modern part numbers for the rubber lines?

Finally got my brake pedal to stay higher. The book says I should have 5" under the pedal. I think im around 4 but hard to get exact with the floor mat. When the truck is running, the pedal will sink to about 2" before it stops. Does that seem reasonable? I shifted it forward and back a few feet in my yard to test and seems to stop fine. Thinking its test drive time this weekend.

Re-adjust the brake shoes, jack up one wheel at a time and spin the wheel in both directions as you adjust. When you have the shoes scuffing the drum step on the brake peddle to center the shoes and check again for light rubbing.

Yup, thats what I did. Dont think they are off enough to make much difference in pedal height. Most likely still a small bubble somewhere I cant get out. It will go higher if i pump with the engine on.

If the pedal is hard, you don't have air in the system. You need the shoes adjusted so there is a HEAVY drag when turning the tire by hand, they should not roll free. You'll have a lot of pedal travel before getting the shoes to contact the drums if they are loose.

Mike B