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Posted by: Rhodes71/914 Oct 26 2004, 10:01 PM

In the process of rebuilding my pedal cluster I put in a new master cylinder. Had to get a pedal cluster from a donor car and rebuilt it. Installed new master cylinder and rebuilt pedal cluster. Filled brake fluid resevoir worked brake pedal. No fluid movement out of resevoir and no resistance at pedal. Do I need to force the fluid into the system? What am I missing?

First time.

sr

Posted by: Series9 Oct 26 2004, 10:15 PM

If you read instructions in most manuals, they suggest priming the mc before installation.

I don't do it, but I sometimes need to use a little compressed air and a little creativity with the cap to pressurize the system momentarily to get the fluid moving.

Posted by: Lawrence Oct 27 2004, 05:35 AM

No resistance? None at all?

Did you get the plunger (that hinges on the brake pedal) inserted into the M/C?

-Rusty

Posted by: URY914 Oct 27 2004, 07:35 AM

That would be my guess too.

M/C needs the rod that is attached to the pedal.

Posted by: SLITS Oct 27 2004, 10:18 AM

The first thing is if you got the pushrod in the center of the cylinder - I use an 11mm wrench to hold the pushrod in midposition and slide the MC over. I won't say why I developed this method

Secondly, is the length of the pushrod - it really shouldn't be a factor, but if it is to long and doesn't allow the piston to fully return, you will never be able to build pressure.

Posted by: Rhodes71/914 Oct 27 2004, 01:03 PM

I guess I assumed since everything went back together fine that the push rod was in place inserted in the MC. Is it possible to have everything assembled and the pedal working correctly (no funny noises) and still not have the push rod in the right spot.

Posted by: SLITS Oct 27 2004, 01:24 PM

Yes - did it twice.

If you want to confirm, pull your pedal board and look - a real PITA.

And to bleed the mc, I crack the tube fittings at the mc and let it drip or push the pedal and let it drip (Yeh, I'm not an environmentalist whacko)

Posted by: Rhodes71/914 Oct 27 2004, 08:13 PM

The rod is correctly placed inside the MC.

Seems I just needed to get some pressure into the system to get the fluid down into the MC. Got all but the left rear bled. Can get nothing to come out of that bleed valve. More work.

Posted by: Lawrence Oct 27 2004, 08:34 PM

Cool... glad it's working out.

Sometimes it's a PITA... and it sucks wasting perfectly good brake fluid.

-Rusty

Posted by: Brad Roberts Oct 27 2004, 10:39 PM

I'm with SLITS. Bleed the lines coming out of the MC.


B

Posted by: SLITS Oct 28 2004, 07:17 AM

Pull the bleeder screw completely out. The ball in the screw could be frozen. See if you get fluid out of the hole.

My "new" bleeder system is an electric vacuum pump. Kinda like the ones they used in M*A*S*H to aspirate fluids from patients. I hook up the line, turn the pump on and go get coffee or ?.

Posted by: Rhodes71/914 Oct 28 2004, 10:05 AM

What kind of electric vacume pump, I was thinking of getting a Mitty Vacand trying that.

Posted by: SLITS Oct 28 2004, 10:13 AM

I will take an image of it - it is old (like me). The Mity-Vac will work but requires you to pump it by hand <_< - I'm just lazy. Will edit this post with an image late today.

Posted by: Eric_Shea Dec 12 2004, 04:30 PM

God, you are lazy...

Posted by: spare time toys Dec 12 2004, 04:51 PM

That is what I use, they work good for me.

Posted by: Brett W Dec 12 2004, 05:03 PM

Bleed screw do not have a check ball in them, unless you are using aftermarket speedbleeders. You do need to bleed the master. It can be done by having someone actuate the pedal and someone to crack the lines on the master from underneath.

You are better off pressure bleeding instead of using the vaccum pump method. Air tends to get past the threads on the bleeder screws and back into the system. Take a spare master cylinder cap and drill a hole in the middle of the cap. Thread a quick disconnect air fitting into the cap. Seal with epoxy. Screw cap onto the master cylinder and hook up air line. Make sure you have a full master cylinder and make sure you regulate the air pressure to less than 30 lbs. Any more and you make a big mess. Then go inside and pump the pedal very slowly. Check the master frequently as you will go through some fluid quickly.

Posted by: scott thacher Dec 12 2004, 06:27 PM

just so you all know slits vacuum pump came with his penis pump

open the lines at the mc and walk away for an hour it will work its way down

Posted by: Rhodes71/914 Dec 12 2004, 06:46 PM

Thanks for the additional info guys but I got this taken care of back in October when the thread was started.

I think Eric must have been doing a search, found this thread and was giving SLITS a hard time because he never posted a pic of his pump.

Brakes work fine now but engine transplant is underway so they aren't getting used.

Posted by: Eric_Shea Dec 12 2004, 07:39 PM

Ahhhhhhhhhhhhhhhhhh... correct (kinda)

I can imagine where this thread is now headed and "NO SLITS... WE REALLY DON'T WANT TO SEE A PICTURE OF YOUR PUMP!