Defective new master cylinder?

[wander2039]

Anyone have one before on here? Based on what I read with a quick search of internet it's quite common. Tried replaced the MC on the Festiva today and I tried bench bleeding it at least 3 times. It's almost like it's trying to suck the brake fluid backwards. I'm taking it back on Monday, took off today to get this done with the snow and colder temp coming so much for that. Tempted to just go with a new.

 

[97prizm]

Eric,

Yes I have heard about it happening. A friend of mine who owns a racing shop said that he purchased a new master cylinder for a 1984 Mazda RX-7 and that it never would bleed correctly. What brad of mc did you buy?

 

[4ever4d]

Possible.I purchased one a couple years back that worked fine but leaked all the fluid out overnight after bleeding and installing man was i off the hook on that one,just happened to see the puddle under the truck before driving off with no brakes.Replacement has been working fine since then.Was leaking where plastic fill tank mounted to cylinder.

 

[wander2039]

It's a Fenco from Autozone. I'm starting to remember why I didn't shop there for years. No leaks just doesn't work.

 

[Johnny248]

Originally Posted By: Eric Smith
It's a Fenco from Autozone. I'm starting to remember why I didn't shop there for years. No leaks just doesn't work.


Not to question your ability, but just had a couple of questions. Have you ever replace a master cylinder before? Did you try just bleeding it on the car and not bench bleeding it?

I used to bench bleed them because that is what I always thought was the right way to do it, however the last 15 I've done I simply bled the brake after installing the master on the car, and have not had any issues at all. Ford service manual does not say anything about bench bleeding your Festiva MC before installing it. It says, install it, and bleed system.

 

[MarkM66]

How did you bench bleed it? With plugs or lines back to the reservoirs?

I'm not sure if it matters, just curious.

I've done it both ways, I've also installed a few m/c without bench bleeding them, with no problems.

 

[wander2039]

This is the first MC but I have bleed brakes many a times. I tried bench bleeding, regular bleeding and combo of the two several times. It doesn't look like there's anything coming out of the front port. There's plenty of pressure out of the rear port which controls the passenger front and part of the rear. When I bench bleed I just put the tubes in a jar of brake fluid. Although that is a better idea.

 

[wander2039]

On further reading on the web if you don't have the MC level the air won't get out of the front. I don't recall the instructions saying anything about this. Just states to clamp it in a vise which would be how it sets in the car, slightly tilted. I'm going to give it a whirl again before I take it back.

 

[sciphi]

The remanned MC on the Buick took a LONG time to bench-bleed. After getting the big bubbles out, we took forever in bleeding out the smaller bubbles. There were several small ones that could not be gotten. We bled it out on the car, and the brakes are rock-hard at the limit of travel.

The MC was held level on a bench vise to bench bleed it.

 

[wander2039]

I got it to bench bleed good no bubbles. But as soon as I put it on the car nothing. The pedal goes to the floor with absolutely no resistance. I tried putting the mityvac on the bleeder to draw out the air or at least some fluid to the rear wheels.. nothing. It's going back here in a bit I'm not sure what else I can do. I remember why I stopped going to Autozone years ago.

 

[wander2039]

Finally have brakes! I returned the MC to Autozone and they didn't have another so I got my money back. Went to OReillys had to wait 2 hours but I literally had it installed and bleed in less than an hour after I got it. The OReilly mc is a cardone brand. I could even tell a difference bench bleeding. I could almost party now...