fluctuating idle only when warmed up
04-14-2005, 10:23 PM
#31
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This is killing me! I sprayed the hoses and connections with soapy water and no signs of leaks. So now, I have is a car that leaks vacuum when I use the brakes....Could it be leaking from the master cylinder yellow valve? or the Blue and black check valve? That's the only thing I can think of.
If I unplug the large vacuum hose that goes from the brake booster and then to the venturi....it runs fine but with no power brakes.
what should I check now?
If I unplug the large vacuum hose that goes from the brake booster and then to the venturi....it runs fine but with no power brakes.
what should I check now?
04-14-2005, 10:37 PM
#32
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Did you pressure test the entire system? To find all my leaks I actually bought a pressure regulator from sears (which happens to be the manual boost controller that certain people sell, didn't know that before I switched to Apex-I's EBC) Anyway I removed my air intake filter and used a large can with a clamp to seal off the intake. I then put 5 then 10 then 15psi of pressure at my banjo bolt connection (you should be able to use one of your vaccuum lines or intake manifold lines. From there you'll find any intake leaks in the system including the brake master.
Brent
Brent
04-15-2005, 11:43 AM
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Yes, you have to pressurize to find leaks!!!! took me a day to isolate several sections also. Use a big WD40 can or something and put in place of the AFM, and clamp around it!! I used a bike pump on a vacuum adapter plastic Y piece you can get from auto parts store, and vac hose, routed right into manifold where fuel regulator banjos come out! Then youll find (sometimes several) leaks.
04-15-2005, 11:58 PM
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Man, I'm having a hard time pressurizing the system. I am using a bike foot pump. I'm pumping forever with no pressure build up. And to top it off, I broke off the small nipple on the brake booster check valve! I fixed that with some drilling and epoxy. Tomorrow I will buy a 5 gallon air tank to try to pressurize the dam thing.
04-16-2005, 11:40 AM
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Ok if theres a major leak somewhere you wont see anything. Heres where a pressure gague hooked onto the T helps alot, since you can see if pressure holds (then a bike pump is just fine). My hugest leak was at the crankcase breather hose in front of the turbo inlet. Pull the hose if you can, and leave it out, and put a 3/8in drive short xtension or socket in the hole in front of the turbo, and clamp down on it to seal it. Then resume testing, which should make all your OTHER intake leaks very apparent. Blowing all the manifold pressure into the crankcase was definitely causing pressure test problems for me, as it leaked right where the dipstick pipe plugged into the oilpan.
04-16-2005, 12:23 PM
#41
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Drifting: You could have a bad yellow brake booster check valve, or the seal on the check valve-to-brake booster could be bad.
Go to a fuel station and use the air compressor over there, that is what i did and works fine
Go to a fuel station and use the air compressor over there, that is what i did and works fine
04-16-2005, 12:45 PM
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Pull the big hose to the vacuum assist off, not at the acutal yellow booster valve, but the other end of that very hose, and pump down on it or pressurize it, and look for leaks/pressure drops. Reconnect it, and further down its line, etc. in stepwise fashion. Break off vacuum circuits into segments you can troubleshoot in piecewise fashion. This way you find ALL the leaks, major and minor.
04-16-2005, 08:58 PM
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Thanx for all the help guys....I found some leaks. All were at the venturi! I still have to check the brake booster Seal and yellow check valve,,,,
Thanx again
Paul
Thanx again
Paul
04-16-2005, 11:04 PM
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Oh I wish I was done......I hooked everything back up hoping that was it. Now it doesn't do it all the time. Only when you leave the brake pedal down for longer than 30 seconds or so. What's weird is that I hear air coming from the brake pedal the whole time I have it pressed. Is this normal?