I set up my brake system with (2) 10psi residual valve 1 front 1 rear! Worked great for a short while.... Put about 150 or so miles on it and now I have to pump the pedal to get the brakes up. I've narrowed it down to the front. Going to assume the residual valve took a poo.... I'm using speedway brand valves. Anyone have any preference on a more reliable brand? These little guys are 35$ each and I don't want to have to replace them every 150 miles. Thanks! All input is appreciated!
Also if you need more info it's a '40 set up... New master from earlfordparts.com and completely rebuilt drums.
I would think Speedway might make it good with only 150 miles on it. $35.00 seems a little high, but with freight it adds up fast. http://www.summitracing.com/parts/wil-260-1876/overview/ Cool looking truck.
Guess I was wrong! It was 35 for both.... Doh. None the less... http://www.speedwaymotors.com/Speedway-Drum-Brake-Residual-Valve-10-PSI-Polished,32110.html Thanks! Maybe I'll try the wilwood this time.
It might not be the Residual Valve is the problem. First re adjust the brakes and Re bleed. This will help eliminate any other potential issues before you look at the line valve. If you still dont have brakes up front the next question was this working correctly before you installed the line valves or is this a new installation? If its a new installation , do you have the correct master cylinder to correspond with the unit. If it was an old installation up graded you could have contamination in the check valve preventing it from operating correctly. These units can be cleanned with brake clean. My opinion the better units are the brass ones made by ECI in CT. The aluminum units are for race car application and really not intended for street use because of corrosion issues.
Having to pump the brakes to get the pedal up means that there is air in the system. From personal past experience I am thinking you have a leak in the system that is letting air be drawn into the system. Check all of the connections and fittings in the lines to the front brakes. Especially check any that you flared yourself as even the very tiny imperfection may allow it to suck air in but not show a fluid leak that is visible. I had that happen on the wife's ot mini van when I replaced the antilock brakes with regular booster and Mc and had to swap some brake lines to get things to work.
Why are you even running a residual valve with early ford juice brakes? They don't need one. Posted using the Full Custom H.A.M.B. App!
I used the Wilwood's but I can see how they get a bad rep with them being aluminum and over tightening can lead to them splitting. I hear great things about the brass ECI ones posted above ^^^^.
Yes the brakes were working perfectly before. the only thing that isolates the front and the rear is the residual valves. The master cyl only has one port out and it tee's front to rear. No old units. Everything is new. and I built the lines front to back.
Not necessarily. The springs on the shoes over comes the pressure in the line and pulls the shoes away from the drum. Then you have to pump the pedal to get the shoes back against the drum. When I first installed the valves when you would spin the wheel off the ground you could here the shoes dragging ever so slightly now... they pull so far away the wheel will spin forever with no drag, this is why I think it is a failed valve. I will tighten all fittings again but there are no fluid leaks, and the soft pedal comes back within 15-30 seconds. Just enough time for the spring to pull the wheel cyl back together.
Couple of things. Stock single master should have a residual valve built in, should not need to add external valves. Residual valves will not overcome the the force of the return springs. Not what they are intended to do. Re-adjust the brakes so you have a slight drag again. If they are '39-'41, check for in-correct initial adjustment of the lower cams. Posted using the Full Custom H.A.M.B. App!
The upper hex head cam stop at the 10-2 position of the backing plate is the adjuster for the brake return. These cams prevent the shoes form returning too far and requiring double pumping the master cylinder to get braking. If these cams are broken off or not there the brakes will retract too far and you double pump. If you have 39-41 backing plates the lower anchors must be adjusted before the top stops. The top stops are then rotated out until the shoe just drags on the drum or some times locks the drum and backed off one flat. If you do not know how to adjust old Ford brakes or need a refresher do a search on HAMB or web. The 42-48 only require the upper cam stop adjustment but require the shoes to match the arch of the drums. If you have a stock master cylinder you do not need the residual line valves as the master cylinder already has one installed. I have a feeling that the drums you have are oversize by too much and as the brake shoe wears the high spot it looses the correct adjustment. Quick question, do you get brakes back after pumping pedal twice or do they remain soft?
On my iPhone. Sorry this message is short. Yes after I pump 2wice the pedal comes back. I will re adjust the drag on the brakes. Possible everything loosened up.
It was the valves. Purchased a pair from ECI last month and just got around to installing them this afternoon. Truck has sat for about 2 hours and the pedal is still solid. Thanks for the help guys. Joe
Well, I'm glad it appears to be working, but there are 2 issues here. 1, if it is an early Ford master cylinder, it should have a valve built in. 2, If it isn't an early Ford cylinder, and does not have a valve, as it is a single port cylinder, just one on the exit of the cylinder would have done the job. You could tee front and rear after the valve. You seem to be adding unnecessary complexity. I just use all early ford stuff and put them together like Henry did. Nice looking truck by the way. Mart.
Mart, I have the same setup as this 32 pick up from the original post... And I too had to run residual valves. My system was all the same, all new master , all new brakes. Adjusted brakes properly . No air leaks, no fluid leaks. Even with the shoes adjusted out to the drum, I had a soft pedal. It was fluid coming back to the master. If you pumped it 2 times, it was hard as a rock as stayed that way under pressure. Installed 2 residual valves, fixed it right up. I didnt have this problem on my model a when I switched it over to 40 brakes, but when I lowered the car and the wheel cylinders where higher than the master cylinder, that's when the troubles began Mines assembled how Henry did, pretty sure these new repop master cylinders just plan suck ass Posted using the Full Custom H.A.M.B. App!
There still is a question about master cylinder internal residual pressure ports. Something doesnt make sense if you are using a stock early Ford master cylinder and it requires line valves to make it function. The early Ford cylinder already has a residual line valve. This cylinder mounts below the floor board and in stock application mounts below the wheel cylinders so adding extra valving is in question, if you dont need it stock, why do you need it now? My question is what are you using for a master cylinder? This may have more to do with your pedal stroke ratio or pushrod adjustment than the master cylinder. What is or who made the brake pedal assembly?
In my experience the Chi-com "hotrod" "corvette-style master cylinders are garbage. USA made cylinders 39-48 Ford or even Corvette should still be available… buy them.