Can’t Bleed rear brakes (Page 2/3)
Sledgehammer APR 19, 04:04 PM
OK guys, A couple of bits of info here. I removed the brake light assembly from the Proportioning valve. I was able to move the sliding pin inside the prop valve. Yes, the brake light was on before I did anything including the annoying gong/beeper.

Using a small sharp pick tool I waS able to slide the pin back and forth somewhat. If I push it forward 1/8” I see a gap in the pin. If I move the pin backwards (towards rear of car) I can only go about 1/8” until the gap disappears and is filled by the body of the pin. With the gap appearance in the brake light hole I replaced the brake light switch assembly. Turned the car on and the brake light was off and NO gong/beeper.

What I don’t know and could use some help with is: How far back and forth is the pin supposed to move? I didn’t try to move the pin further forward after the gap appeared. Since the pin is not entirely stuck or frozen in place I want to make sure I can move it to where it should be normally.

I know I can source another Prop valve, but I dread attempting to disconnect all those brake lines from existing prop valve.

The real question is how do I know if or where the sliding pin is to be when in the right place. Anyone out there got some insight on this?

Sledgehammer

[This message has been edited by Sledgehammer (edited 04-19-2020).]

Patrick APR 19, 04:31 PM

quote
Originally posted by Sledgehammer:

Yes, the brake light was on before I did anything including the annoying gong/beeper.



Would've been helpful to have posted that at the beginning!


quote
Originally posted by Sledgehammer:

how do I know if or where the sliding pin is to be when in the right place. Anyone out there got some insight on this?



If I can use the Search function here to find this thread... so can you.

Anyone know how to reset the brake proportioning valve?

[This message has been edited by Patrick (edited 04-19-2020).]

Sledgehammer APR 19, 05:46 PM

Patrick,

Thank you. At this point it looks like I have the CV entered and I should be able to bleed the rear brakes while it is centered. That photo/diagram of yours was excellent and told me exactly what I needed. Interestingly, when I had done a previous search on the forumI must not have used the correct key words because that posting and your photo/diagram did not appear. Anyways, I hope I can now bleed the rear calipers and be done. This Fiero as I mentioned earlier had been in storage for about 10-15 years (outside) and I have uncovered several surprises I didn’t expect to find. Especially with only 52K miles. The engine turns over but have not tried to start it yet. Much work to do in preparation for that event.

Thanks again Patrick,

Gerry
Patrick APR 19, 06:15 PM

quote
Originally posted by Sledgehammer:

Interestingly, when I had done a previous search on the forum I must not have used the correct key words because that posting and your photo/diagram did not appear.



It's not just the "key words" used that are important, it's where you're looking. I suspect some people have never investigated the drop down choices. The ones I've indicated below cover the widest parameters.
wftb APR 20, 09:44 AM
Or just use a google search. Usually easier. There is so much info on this forum that sometimes the search results can be huge.

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86 GT built 2.2 ecotec turbo
rear SLA suspension
QA1 coilovers on tube arms

Sledgehammer APR 22, 05:45 PM
FRUSTRATING. I received the tool today to keep the CV slide centered and tried to bleed the rear bakes again using my suction bleeder. NO LUCK could not get fluid out of the rear brakes regardless of how hard I tried.

If you have any thoughts that can help here it would be appreciated.

Status: 1. Have slide centered
2. Can get fluid from front brakes
3. Tried pumping brake pedal, with center tool in place, no help
4. Fluid not leaving Master cylinder, from rear MC tank

QUESTION: IS THERE ANY POSSIBILITY THE PROPORTION VALVE IN THE CV COULD BE STUCK OR INTERFERING IN THE PASSAGE OF FLUID TO REAR CALIPERS? In the CV diagram it shows the proportion valve in rear area of CV which appears to interact with passage of fluid (assumption on m part) I tried to loosen Proportion valve, but it would not loosen. If necessary can retry with more assertion.

Reminder the car did sit in outside storage for 10-15 years, front brakes were locked when I received the car. replaced all calipers, two of mine were rebuilt.

Any thoughts here would be appreciated. If I have to replace the CV any easy method of removing the brake lines from the old unit without ruining the lines or fittings?

[This message has been edited by Sledgehammer (edited 04-22-2020).]

Patrick APR 22, 06:25 PM

quote
Originally posted by Sledgehammer:

if you have any thoughts that can help here it would be appreciated.



I'd disconnect the rear brake line from the LR caliper (furthest from the MC) and step on the brake pedal... but not to the floor. If done repeatedly, fluid should eventually come out.

You can also move the slider in the CV to try and cut off the front brakes while you're doing this. More CV diagrams Here.

[This message has been edited by Patrick (edited 04-22-2020).]

Lou6t4gto APR 22, 06:38 PM
beat me to it, Proportioning valve.
Sledgehammer APR 22, 07:48 PM
OK, removed brake line, tried pushing the pedal. Still NO fluid came out, no depletion in reservoir either.

I did remove the proportioning valve, it came out easily, don’t know what I’m supposed to see anyway, I cleaned everything up and will reposition it back in the CV.

Any further thoughts ?
Patrick APR 22, 08:23 PM
Disconnect the LR hose from the hard line. Without doing anything further, fluid should eventually start bleeding out the open connection. If not, I'd start looking for a spot on the metal brake line that's been crushed flat.


quote
Originally posted by Gall757:

Have the hoses been replaced? They can expand and stop the fluid.




You did get around to bench bleeding the MC, right?

[This message has been edited by Patrick (edited 04-22-2020).]