..Brakes question...

[svofan1]

..One more time I need to tap the knowledgeable people here, afterall you guys are always on the money.
Changed all the brakes (calipers,rotors, pads ) on all 4 wheels then I bled the brakes (twice), but i noticed that the brake pedal is too low and to bring it up I must pump at leat once.
I am thinking that the master cylinder has to be bled (I will do this with the master cylinder in place with the UHELP kid)because last year I pulled everything out to paint the engine bay. I can't remember how the brakes felt before that adventure.
Is there anything else that i should look for if the bleeding of the master cylinder does not resolve the proble?....
Thank you all..

Ralph L(NJ)

[GAboySVO]

Ralph,

I think you are on the right track. You probably have some air in the master cylinder. If after you bleed the master cylinder, the pedal eases down as you hold pressure, then you might need to rebuild the master cylinder.

[Ken Potter]

One other thing...

One other thing is the vacuum check valve located on the booster. It is connected to the vacuum tree on the firewall by a rather large rubber hose. With the ENGINE OFF simply pull off the hose and pop it out of the booster. You can use the old school method of mouth suction test. It should draw air in only one direction of course. They're cheap and pretty much universal. Every parts store should have one. When you have everything hooked back up start the engine but DO NOT PRESS THE BRAKE PEDAL. Rev it up a few times then shut it off. Now depress the brake pedal several times with the ENGINE OFF and the pedal should come all the way up / rock hard. Restart the engine and if it's still low / goes soft then it's master cylinder / fluid related issues.

[svofan1]

..brakes...

..I am glad to see that my favorite people has responded to my question...you guys (the 2 Mikes's and Ken) are my favorite sources for good sound advice. I have seen you guys in action and always admired your knowledge and the maturity in your responses...I will follow your leads and will post results. Thank you Guys!!!....
This is for Mike F...could you expand a little on how to adjust the valves for the emergengy brake at the rear?....
again thank you guys i do really appreciate your help.

Ralph L(NJ)..

[richsvo]

Tecnical talk...

originally posted by Mike Fleming...

The rear caliper has a cam-lock thingie

Mike, there ya go using that technical jargin again...
Rich

[Pat_in_L.A.]

Re: Tecnical talk...

Originally posted by richsvo
originally posted by Mike Fleming...



Mike, there ya go using that technical jargin again...
Rich

Yup, all them multisyllable words kick my butt!

[svofan1]

...ahhh!...brakes!

Thanks Mike, that was a "mouthfull"....I will print your explanation and try to follow it as best as I can...I love the "tech" terms...<S>..one more final thing, after I do all of the above, besides bleeding the master cylinder, should I bleed all 4 wheels again?...
Thanks
Ralph L(NJ)

[Eyelawdoc]

You will have to disconnect the steel lines from the master cylinder to bleed it. Therefore, you will then have to rebleed the system after reconnecting the master back up to the steel lines. I've found one of those Mittyvac bleeder thingies to be a godsend when bleeding the brake system by myself.

One other thought is that a master cylinder with bad seals and internal leakage will also cause a low pedal. I had that problem with my 84 SVO about 9 months ago (and presently have it with an 83 Mustang GT Turbo I just acquired). I replaced the master, bled the master and then bled the system and normal pedal height was restored.

[svofan1]

...brakes...

Thanks a lot....the input on this matter has been great. I will do as indicated and wil report back to the group....
Thank you all for all your help..

Ralph L(NJ)

[svofan1]

..brakes saga continues

Well, I followed all the good advice, bled the master cylinder and the entire system and the brake pedal has to press twice in order to make it come up higher.
The question is who is the must likely culprit, the master cylinder or the brake booster?...which one should I go for first?..i am trying to avoid bleeding the system twice (all 4 wheels).
Thanks for the help...

Ralph L(NJ)

[Ken Potter]

Still sounds like a weak booster to me. Did you try my vacuum check valve replacement / test yet? I only say this because I had a 72 442 prior to my SVO with the same problem you have described. I had replaced the entire brake system including calipers / wheel cylinders but it still had to be pumped to come all the way up. Cost me mucho $$$$$$. I then replaced the cheesy little $1.25 check valve and presto! No more mushy / low pedal.

[Eyelawdoc]

Re: ..brakes saga continues

Originally posted by svofan1
Well, I followed all the good advice, bled the master cylinder and the entire system and the brake pedal has to press twice in order to make it come up higher.
The question is who is the must likely culprit, the master cylinder or the brake booster?...which one should I go for first?..i am trying to avoid bleeding the system twice (all 4 wheels).
Thanks for the help...

Ralph L(NJ)

Can you be a bit more specific in describing EXACTLY what you have done, or have not done to get to this point? It appears you still have internal leakage.

Have you replaced your master cylinder? If not, do it now. You will have to rebleed the system after you have bench bled the master.

[svofan1]

...brakes...

Thanks Ken, I did replace all brake lines, calipers and rotors front and back (it was needed after 20 years..<S>)...and of course bled the system...the problem before and now (as in my previous posts) was that the brake pedal has to be pump once in order to bring it up (while driving of course)...then as suggested here I bled the master cylinder and check that the vacuum hose was good (it was) and then re bled the system one more time. Problem ci\ontinues, ia m thinking of replacing the master cylinder, but I am afraid that the problem may be in the brake booster and then I have to undo all again and the rebled the entire system for the 4th time....I think the easiest way is to replace the master cylinder, as you suggest, and take it from there..right?.
What are the chances that the break booster is bad?...based on your expiriences....
Again thanks for all the help.

Ralph L(NJ)

[svofan1]

..brakes...

..one more thing...can I bleed the master cylinder while mounte?...it appears to be the easiest way sinc i do have the kit with the fittings and it seems to work fine...i don't know how to do "bench bleeding"....it would be nice since I have the replacement master cylinder on the bench already.....

Ralph L (NJ)

[SVOeric]

you can bleed the master cyl either way --

bench bleeding, you just put the master cyl in a vise, connect the hoses, and use a large screwdriver to actuate the piston --

only difference is what you are using to hold the master cyl, and what you are using to actuate the pistion.

the end result is the same