They told him wrong on needing the residual vavles. Did they sell him the right master cyl. for his set up(drum/drum,disk/drum,disk,disk)as far as the internal valving? Did he bench bleed the master cyl.? If not it can be a real bitch to get all the air worked out of the system. I know I almost ran my corrvette through the house because I didn't bench bleed the master cyl. Not that it can't be done that way it's just alot harder.
rear port closet to booster is for front , front port is for rear. when you push pedal you want front brakes to apply frist and rear port moves fluid frist. make sure brake shoes are adjusted properly this will cause a spongy pedal
i say replace the metering valve with a T, the best thing about running drums is that you can keep the shoes from touching the drums all the time, but for bleeding i say adjust your brakes up to have a little drag.
The front brake, rear brake, front port, rear port orientation depends on the internal valving of the master cylinder. Usually the smaller of the two reservoirs is for the rear on a disk/drum set up and the reservoirs are usually the same size on a drum/drum or disk/disk setup master cylinder.
Residual valves are needed on all drum brake applications and only needed on disk brakes when the master cylinder is located below the calipers. One reason for their use is to prevent air from being pulled in past the wheel cylinder piston seals. The other is to aid in overcoming the brake shoe retaining spring pressure. To have more than one going to the front brakes is overkill. Do you have them mounted in the right direction? It may not matter anyways because all of those style residual valves seem to never work right. I have used the wilwood and speedway versions and the brakes would work right for a day at best. I disassembled them and noticed they use a cone shaped one way valve with a flat end that eventually would turn round and fail to seal or hold pressure. After that I started using drum specific master cylinders with the factory original internal mechanical residual valves and was very pleased with the results.
ok so no rpv, and make sure the the bigger resevoir is for the front and the smaller for the back? anything else? im going to see if i can take some pics
This may be a dumb question, but are you using a vacuum assisted bleeder? I have never had a problem until just recently and needed a to put a vacuum on to get all the air out of the system.
loose the metering valve, theres nothing to meter there, you want equal pressure to both front wheels, i also see in the pic of the setup the words adjustable valve, i guess there talking a "Adjustable Brake Proportioning Valve" that would be placed inline to your rear brakes, i dont run one but some do, i think they would be more important with a disk/drum setup, i just set my front brakes up a little snuger then the rears.
Bigger resevoir for front smaller for rear, becouse the disk pistons on front disk system do not return by spring pressure and they are larger. BUT you do not have disk up front! Do you have the correct master cylinder? I don't rembember seeing any residual valves in a drum system. Could be wrong
i tryed using the vacumm gun thing and the old method of some on steppign on the pedal and holding it i dont have a metering valve, i have a "t" in the front and a line going to the back as far as i know i have the correct MC it saids that its for a drum/drum, disk/drum. thay dais for drum /drum to use the rpv
sorry i thought you had gone totaly by the pic of the brake setup, likes others have said adjusting your brakes up first, nice and snug, you can always readjust them, if the shoes have a chance to move back and forth as your pumping the pedel then they just keep any bubbles moveing back and forth and not moveing toward the wheel cylinder.
Again. A residual pressure valve is needed on a drum application. If you want to keep it simple, once you've already checked that the rpv's you're currently using are installed in the right direction,you've bled the shit out of the system and it still don't work right. Go down to your local parts store, buy a replacement master for any GM car that used drum/drum (pre 67 single res. post 67 dual). Bolt it up, connect your lines and that's it. They already have an rpv built in and they are made to last. Just trying to save you a lot of frustration.
My 2 cents...just be sure you adjusted the shit outta the brakes so they're a little on the tight side, if for no other reason just to rule this out as a problem...everybody likes them a little different but I like the tire to spin somewhere around 1/2 to 1 turn depending on how I feel the day I adjust them The guy that owns ECI just spoke up on another thread about brakes that the rear outlet nearest the booster is for the front brakes. Who am I to doubt him?!? That pirate jack diagram is the most cockamamie thing I've ever seen. I don't know what to make of it, but I'd look at some others before deciding to go with that scheme. My bet is.........air in the lines, what a surprise! If you're barely getting fluid to the rear, then you must be getting a bunch of air. Sucks, don't it! Bench bleed the MC then you have the unenviable job of bleeding the rest of them. Here's more free advice-put in some speed bleeders on all 4 wheels, that is about the *best* dang money I ever spent!!! $11 a pair, you can even get tthem in the ooops section at autozone if you're lucky. If you're just one guy like me, they make bleeding brakes soooooo much easier. Good luck and let us know!
Also. The master you've got is probably a universal aftermarket version that will work with a drum/drum, disc/drum but it has no internal rpv's and needs them installed in the lines depending on your application. Basically just an early Corvette master.
That priceless; spring tension in the drum system tends to pull the shoes away from the drums. No chit sherlock lmao This has got to be an employee that is slightly misinformed. Someone already mentioned it on here, go buy a dual master for a 4 wheel drum system, the "2" lb valves are built in. But you gotta be careful some of those old systems only had one valve and relied on the prop valve to equalize the pressure for the whole system. The 2 lb valve is used to keep the wheel cylinder cups "inflated" when you're off the pedal, natural air pressure can get past that seal otherwise. By the way, systems with a prop/diff valve always apply the rear brakes a split second before the front to keep the vehicle straight on initial application. my$0.02
10 lb rpv with drums, a master with only one built in rpv would be used with disc/drum, proportioning valve is only used with disc/drum also. Trying to keep it from getting confusing.
Factory drum brake cars with dual res. masters did use a brass manifold under the master cylinder but it only contained a pressure differential switch (idiot light) and or safety valve.
ok i called pirate jacks and they confirm the rear resevoir is for the back and the front in for the front, they told me to check the pedal ratio. ill im going to try a few things that were mention in this thread thanks to all yous in advance and let me know if there is anyhting else
ok thanks to all you guys that reply, i took all the valves off and i got it to bleed but there was alot of play on the pedal felt spongy. so i pit the 2 valves on the front and left nothing on the rear and the car bled and the pedal felt like it never felt b4, test drove the car and it handles and brakes better than my daily witch has for wheel discs, so only taking the valve going to the rear out fixed everything. like i said b4 thanks to everuone that left a comment
The valve may have been defective. Did you check to see if it was going in the right direction or clogged w/debris? I'd put a new one back in later so everythings kosher. Like a Hebrew National hot dog. See ya later.
Chief, You use a 2 psi residual pressure valve in a disc brake system if the master cyl. is under the floor. It's used as an anti-siphon valve to prevent the fluid from siphoning back to the m/c when you get off the brakes. You ALWAYS use a 10 psi RPV in a drum brake system, it is an anti air ingestion valve that prevents air from entering the system past the chevron style seal used in a wheel cylinder-period. Depending on the m/c they may be in the cylinder, behind the seat in the outlet port. They are not cumulative so if you are not sure put one in it won't hurt any. If you put on all new shoes and turned the drums there is a good chance that the shoes don't fit the drums real well since you can't have a shoe arching machine anymore (feds outlawed them), and that could be some part of your problem. Drive it a little and check the shoe contact pattern, you can use a sanding block to make them fit better, WEAR A RESPIRATOR WHEN SANDING.
ECIGuy, I can not say how glad I am to see you join our ranks. I learned a lot from your reply above. Much appreciated!
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