[JJman]

'94 RMS. I changed the RR wheel cylinder a year ago and all was good. Recently it's been pulling a little to the left during braking so I set out to bleed the RR the other day. Wife was pumping the pedal as I worked the bleeder. I had the cap on the MC too loose at that time and some fluid squirted out. When I realized it there was still some fluid in the front and rear chambers. Continued bleeding that RR but a very small amount of bubbles continued to come out for what seemed way too long. It didn't seem right to me and we stopped for the evening. I got in the car to move it and started the car. The "brake" light was on and depressing the pedal turned it off. But the pedal went almost to the floor, even after pumping. It had that feel of a bad MC which made sense because the fluid was nasty enough and cycling the old MC during bleeding could have torn a cup. So I bought a rebuilt and bench bled it fully and bled the outlets on the MC properly during installation. (The lines were capped when not in the MC.) Still a very low pedal with the same feel. So I found a new one online (Fenco) and put it on with no improvement.

I understand I may have introduced air during the initial session and need to re-bleed (all wheels this time.) The problem is that it does not have that “spongy” feel of air. Rather it slides right down with very little resistance until near the end, with the engine on. With the engine off more foot pressure is required but the problem is still there. The drums are adjusted properly and all shoes/pads are meaty. No lights on dash. The brakes were performing well (with the small pull) before this. The chamber towards the vacuum booster squirts fluid up while the pedal goes towards the floor. All 3 units did/do this so I’m thinking that’s normal. In the past this type of feel has always meant a bad MC, at least for me. I’m seeing differing statements about the ABS needing bleeding. I don’t think it has any “bleeder screws” on it.

I’m leaning towards getting a full pressure bleed since it’s probably a good idea anyway. But I’m wondering if anyone knows of an obvious thing I’m missing. cwm3

 

[JJman]

So I brought it to Midas for a pressure bleed. They told me both wheel cylinders have fluid inside the dust boots. I didn’t know that was a way of checking wc’s. I had always assumed there would be visible leakage but this makes sense now. So they wanted to change them and one caliper that has a bleeder stuck. I told them I do that type of work myself and there was no charge.

As I thought about it I started to understand that the wc’s were leaking into their boots and this was preventing the fronts from kicking in properly because of the proportioning valve doing it’s thing. So I changed them tonight and all is good again. Funny thing is I now see that I had changed both of these wc’s over the last 3 years or so. Made in China "Wagners." The new ones I just picked up are also Wagner and they had 2 different looking styles in stock, both made in China. I went with the style that is not the same as the ones I bought last time.

 

[ghetto wagon]

Time to look for the USA wheel cylinders! Its very hard to find USA (or north america) drum brake parts these days

ABS does not need to be bled, Just bleed the wheels regularly and you will be fine.