HANDBRAKE NOT GOOD ENOUGH FOR TEST (Page 3/5)
Darthscooby1001 DEC 02, 11:46 AM
Ok, I changed the master cylinder today. After bench bleeding it, I bled the pipes after putting it on, then all 4 calipers. I won't say they are wonderful, but the brakes are working as good as they previously did.

Back to the handbrake. I have readjusted everything again and was quite confident, as I could not turn the rear wheels at all. however, the handbrake handle now comes up past 11 clicks and runs out of clicks! The equaliser is adjusted as tight as it can be, but there is still slack in the L & R cables. The levers on the calipers are in the right place and the hand brake does feel better. However, I test drove the car up and down the street and only once did the car stall pulling away with the handbrake on. Each time after, it just pulled away regardless. I doubt it will hold the car on the rollers, so I now need to look for other solutions as the cables appear to be too long
theogre DEC 02, 12:57 PM
Follow P-brake "adjustment" in cave.
This and other methods are not a good adjustment but give you an idea what is wrong because Too much pad clearance is never going to have P-brake working. Main pedal is often "low" trying to stop normally too.
Basically Caliper levers will tighten on the shim w/ lever moving only a little. Little I mean next to nothing. A bit more w/o the shim. And that's w/o pushing the pedal.
Why? "Rebuild" calipers are often bad and pistons won't self adjust and the "adjustment" might help but soon have same problems again or worse.

Is raining so can't take pictures etc of p-brake on my car.

Might be wrong cables for each wheel, main cable or all of them.
Where did you buy them? brand and PN for them?

[This message has been edited by theogre (edited 12-02-2019).]

Darthscooby1001 DEC 04, 08:29 AM
Thanks again guys.

Ok, after adding an extra block to the end of each brake cable at the calipers, I was able to shorten the length and could adjust tension once more at the equalizer. Handbrake now pulls up to about 8 clicks. The Wagner cables I bought from Rockautos were not longer, but the stopper on the ends of the cables that are more towards the end, adding a total of approx. 4 cm. Too much for the equalizer to adjust. But I know now. Hope that makes sense?

Anyway, I carried out all the adjustments from the cave and was confident I had it right... Yeah, the handbrake failed miserably on the rollers. It reached level one and the guy said it should reach level 3-4 to work. What was worse even, the normal foot brake was no better and didn’t even slow the car down on the rollers! I am beginning to think that perhaps the handbrake was never the problem and there is a braking problem instead. The pedal does not sink to the floor like it did prior to changing the master cylinder, but it does travel halfway down before beginning to slow the car! I think first I am going to inspect all of the lines and hoses then start and bleed everything once again.

I’ll be back after that.
mcguiver3 DEC 04, 09:22 AM
I'm not a brake expert but after owning 6 Fieros over the past 25 years I've had my share of brake issues.
Have you replaced the flex lines at each caliper?
Are the rotors running true?
Caliper slides working properly and lubed?
Is the proportioning valve working properly?
Sounds like the master cylinder was replaced and bench bleed as were the calipers.
Not much left to check.
theogre DEC 04, 11:43 AM
Low and/or soft pedal is often a big sign still have air in the system, Too much pad clearance, or both.
Hoses won't cause this but may need them anyway.
The "proportion" valve part of the combi valve likely isn't a problem here.

Sliders and other brake parts needing lube need Brake Grease. Many other lubes will ruin then now or soon.
Slider "O-rings" are "return springs" for outer pad. Normally Outers have just enough clearance to not drag them. IOW most times Won't slide w/ you pushing/pulling easy but will w/ brake pressure as needed.
Front inners are about same because main piston seal is "return springs" for it.
Rear piston has springs and seal as return springs. Big problem is same springs in iffy pistons can force one part out (Back part w/ bearings) and cause big problems. Even cause brake failure or a fire by dragging the pads hard.

Note: iffy wheel bearing(s) can cause pad/caliper issues.
Front bearing are not Preloaded but too loose then too much play in a wheel and rotor forcing too much clearance. See my Cave, Front Bearings
Rear is same but "non adjustable." If "loose" then bearing are iffy/bad or axle have problems causing loose bearing.

When you buy New caliper hoses, should be newer SAE J1401 "rubber." DOT hose w/ Non SAE rubber will work but not as good. Don't buy SS hoses. See http://www.fiero.nl/forum/Forum2/HTML/129208.html

What Pads do you have?
Because Many sold thru Ebay and other online "stores" claim "Race pads" etc may need high heat to work and never get hot enough driving on the street and won't help you.
Darthscooby1001 DEC 12, 12:06 PM
Update from the latest test on the rollers. I waited for some adapters to arrive so I could bleed the master cylinder to death (tubes back into the reservoir). Then I bled the pipes followed by all four calipers many, many times until not even a minor bubble could be seen. The foot brakes works great now and even got an emergency use: as some idiot jumped in front of me…..! Sadly, on the rollers the handbrake still did not reach the measure the garage say it should be. They are at 19% now, which is better than previous attempts.

Almost every part of the braking system has been changed in this car. There are no leaks and Booster is working normally. I think I must now look for a new Test Inspector. :\
olejoedad DEC 12, 01:22 PM
The handbrake is completely independent in operation from the hydraulic system. I'm glad the hydraulic system is working better for you.

Questions for you concerning the parking brake issue.....

- How much slack in the cables when parking brake is not applied?
There should be no slack in the cables; there should be slight tension.
- How much clearance between the pads and the rotors when the parking brake is not applied?
There should be as little clearance as possible between the rotors and the pads, on both wheels and on both inner and outer pads.
Darthscooby1001 DEC 12, 02:34 PM

quote
Originally posted by olejoedad:

The handbrake is completely independent in operation from the hydraulic system. I'm glad the hydraulic system is working better for you.

Questions for you concerning the parking brake issue.....

- How much slack in the cables when parking brake is not applied?
There should be no slack in the cables; there should be slight tension.
- How much clearance between the pads and the rotors when the parking brake is not applied?
There should be as little clearance as possible between the rotors and the pads, on both wheels and on both inner and outer pads.



Thank you (and everyone for their help so far)

Easy answers here: There is next to no slack in the cable and I can pull the brake up to about 7-8 clicks now.
There is little to no clearance. I actually think they are too close, but the wheel does rotate without much effort.
olejoedad DEC 12, 02:39 PM
There should be more tension on the cables. The cables should be in tension against the return springs.
Will DEC 12, 02:42 PM

quote
Originally posted by Darthscooby1001:

Update from the latest test on the rollers. I waited for some adapters to arrive so I could bleed the master cylinder to death (tubes back into the reservoir). Then I bled the pipes followed by all four calipers many, many times until not even a minor bubble could be seen. The foot brakes works great now and even got an emergency use: as some idiot jumped in front of me…..! Sadly, on the rollers the handbrake still did not reach the measure the garage say it should be. They are at 19% now, which is better than previous attempts.

Almost every part of the braking system has been changed in this car. There are no leaks and Booster is working normally. I think I must now look for a new Test Inspector. :\



Have you checked to make sure your calipers are assembled correctly? That is, that rotating the arm the direction the cable pulls it results in the brake actually applying. This should be done on BOTH calipers.
Remanufactured calipers are sometimes assembled with the wrong parts, meaning that the mechanical components are "backwards" and pulling the cable actually releases the brake.