New M/C is about $20 from Rock auto, might not be a bad idea anyway if you already have to bleed the brakes. This a GREAT build by the way
New M/C is about $20 from Rock auto, might not be a bad idea anyway if you already have to bleed the brakes. This a GREAT build by the way
If you have a lot of air in the brakes, you can run a piece of hose from the brake bleeder up higher, vertically, than the master cylinder and let it sit like that overnight.
This helped me when I replaced all my calipers on the racecar.
It gets you close enough to be able to do a normal bleed from that point.
In reply to Agent98:
Thanks! Glad you like it!
Thanks everyone for the tips and the help. I believe I've found the root of the issue. I started loosening fittings until I found the one that fluid didn't come out of. It appears that the junction block is the issue. When I took the line that goes out of the junction block and too the rear brakes off, no fluid would come out. So I think that should be the issue.
If you're talking about the proportioning valve/brake light switch/junction block that is below the master cylinder in the engine compartment...I've been there and done that. If one "side" of the system (either front or rear) has a leak and won't hold pressure, the valve locks that side out. Getting them re-centered is not always a trivial matter (but I'm sure sometimes it is easy).
One thing to keep in mind here here is that you PROBABLY had a leak in the rear brake circuit (and that's why the valve closed off that circuit). Whether you fixed that or not installing the different rearend is what remains to be seen.
In reply to ClemSparks:
Have any tips or know how on re-centering it? I'm doing some googling now, but figured i'd ask anyway.
Well my zephyr blew a front line when my wife drove it home as a present for me. Its still not working correctly. Even tearing it apart and cleaning it cant get it to not lock the rear brakes up before i get any fronts. I bypassed it with some shadetree fittings but finally caved in and purchased an adjustable combo block from speedway.
On my fox body, I believe I tripped the valve while trying to bleed it or by not having bled the brakes before applying full force to the pedal. I couldn't get it to reset/recenter. I ended up "gutting" it per the advice of several threads I found on the web. I was changing enough stuff around that I probably needed an adjustable proportioning valve, regardless, so this was a passable option at the time.
On my Malibu, the thing was tripped when I got it (for who knows how long) and had been in my ownership 3 years before I got around to doing much with it. It had a cast iron prop. valve and I figured it was done for. I bought one through summit to replace it. I still don't have it on the road yet, but should soon.
No matter how much I googled, I couldn't find much that actually made me think anyone out there actually KNOWS what's going on inside of one of these "Combo" valves.
In reply to ClemSparks:
If I gut the stock valve, I would then want to put in an aftermarket valve right? I'm already quite a ways over my budget, so i'm trying not to spend more than I have too. However it is the brakes, so i'll spend the money for the safety aspect.
IN the case I do need an aftermarket valve, any recommendations?
Wouldn't gutting the valve tie the two circuits together at that point, effectively giving you single circuit brakes? That would be a bad idea. You'd want to replace it with an aftermarket prop valve on the rear line and a plain splitter block for the front lines, if you're using one put the hydraulic brake light switch on the front circuit.
Some motivation (I hope the vid works): https://www.youtube.com/embed/DSNpTsCVwH4
NBraun wrote: In reply to ClemSparks: If I gut the stock valve, I would then want to put in an aftermarket valve right? I'm already quite a ways over my budget, so i'm trying not to spend more than I have too. However it is the brakes, so i'll spend the money for the safety aspect. IN the case I do need an aftermarket valve, any recommendations?
I believe that's what I remember is the prevailing wisdom (I'm sure you've looked around and can confirm that's what folks are saying). I was changing my brakes all around anyway so I figured I probably needed an adjustable prop valve anyway. I just searched summit's site and found one on sale or such (edit: here's the one I got). There's a convenient spot to install one on a fox body over at the passenger side of the firewall in the engine compartment.
Strangely, I don't think that "gutting" the prop valve actually allows the two circuits to be connected. But again, I couldn't find enough info on the web to make me feel I confidently understand what's really going on in there. I'll see if I can dig back and find some photos of what I did in the Mustang. (edit: I looked and don't find any photographic evidence to jog my memory.)
Why bother gutting the stock one, just replace it with an adjustable combo. There less then 100 bucks from speedway and it saves you adding extra fittings.
In reply to dropstep:
Is something like this what you mean? Valve
I'm thinking that might just be the easiest option. If i go the other route, I need to buy a $20 plug if I gut it, or a $20 eliminator kit. I took the plug off the front and tried to manually push the rod back into position, and couldn't get it to move at all, so I guess that seals the deal.
In other news the throttle cable was installed last night, so once the brakes are figured out it can take it's maiden voyage.
I welded the hole in the vented cap rather than buy the $20 plug. That valve you linked to is probably a pretty good choice. It does not appear it will bolt in without bending (and probably flaring) some brake lines...but that's really not a huge deal if you're cool with bending and flaring lines.
I thought there were some combo valves out there that are adjustable and bolt-in for some GM applications. I was hoping there would be one for your application but I looked around and don't find it. That would be a no-brainer if available. Here's the one I was thinking of...but it appears to also be a universal one. Still under $100 at the usual online outfitters: http://www.classictube.com/catalogsearch/advanced/result/?ymm_cat=Proportioning+Valve
In reply to ClemSparks:
I guess I assumed that cap was brass and couldn't be welded. I suppose if it was I could have found some brazing wire.
At this point I don't think I'd mind bending and flaring new line, I have extra from replacing the broken line.
Thats identical too the unit i ordered from speedway. ive already replaced the lines on my car twice so i figurd one more set for a solution would be worth it. Its standard 3/8x24 threads so your stock lines out of the factory valve will fit if you mount in stock location. Speedway included all the needed fittings with mine.
Well I received my proportioning valve. I ended going the cheaper route and welded the stock vent hole, and bought the $40 inline valve. I put it on the passenger side, between the stock line, and the line I made going to the rear. The good news is that was the issue and now i'm flowing fluid to the rear. The bad news is that fluid is leaking from the center of stock fitting on the passenger side. I need to buy a few fittings before I can make a new line, so waiting again.
Remade the line, got everything sealed up. I was able to get fluid out of both rear bleeders. However, the brake pedal never seemed to stiffen up. Eventually I thought to push it as far as I could and I proceeded to blow the passenger side front brake line. I bent up a new line and got as far as I could. Had I known I would have been redoing most of the hard lines I would have bought a much better line flarer.
NBraun wrote: Remade the line, got everything sealed up. I was able to get fluid out of both rear bleeders. However, the brake pedal never seemed to stiffen up. Eventually I thought to push it as far as I could and I proceeded to blow the passenger side front brake line. I bent up a new line and got as far as I could. Had I known I would have been redoing most of the hard lines I would have bought a much better line flarer.
my cars not really rusty and i still ended up having to replumb the entire brake system after the first line failure. Running the rear brake line inside like they did from the factory was a treat.
In reply to dropstep:
You have more patience then I. I just ran the line underneath the car.
I do have another question though. I've got all the lines on and started bleeding the brake's again. I'm using a vacuum bleeder and believe to have the air out of the lines. However I can't seem to build much pressure. The pedal is mostly loose, until the second half of its travel, where there is a slight resistance. Is it possible since the reservoirs were totally drained I need to bench bleed the master cylinder? Even if there was air in the lines, you would think I could still build up pressure on the pedal.
I'm too lazy to reread previous pages. if this car has rear drums, make sure the adjusters have the shoes just barely dragging. long pedal travel on cars with rear drums is very often the result of shoes not adjusted properly close to the drum.
it is also possible that you berkeleyed up your master by stroking the pistons into part of the bore where they normally don't go, nicking a seal on a rusty spot and creating an internal leak.
fill the reservoir, open ONE bleeder screw, put one end of a 3' long piece of clear tubing (from home depot etc) over the bleeder and rig something to hold the other end as close to straight up as possible. this will allow you to watch the system gravity bleed, one corner at a time.
sounds like the same issue i was having that required a new master cylinder. Bleeding the brakes pushed the piston past the rust ring that had built and left a small tear in the master seal. Id start with a bench bleed and a double check of the rear adjusters like the guys above me said.
Well I bled the master cylinder and I believe I've fixed it, but well see just to be sure.
In other news I took it for a spin today. The used CL th400 goes forward and reverse, so that's good. It has a terrible vacuum leak, the turbo oil feed is leaking, it runs pig rich, and I believe it is burning a bit of oil, and when I shut it off, a bunch of white smoke came out of the stack. Luckily these all seem to be pretty simple issues, so hopefully i'll be able to knock em out and get the car on the road.
Buttoned up the rest of things on it and got it to start and idle. I hope to start street tuning it tomorrow. I need to do some learning on street tuning with megasquirt, as this is the first time learning anything like it. https://www.youtube.com/embed/8HxuAhQ2ps4
So I'm looking for some tips or help with bleeding the cooling system. The water pump outlet is higher than the radiator and I believe that's my issue with getting it bled. The car keeps wanting to overheat, and even with the radiator fan maxed out the temp still rises all the way up to 210-220 before I shut it off.
Any ideas?
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