Brake bleeding (Page 1/1)
Zentaury JUN 15, 01:26 PM
I have a couple of questions.

1) Is possible to bleed the brakes by the banjo bolt?

As you may know I got this car recently, the ebrake was stuck and the rear hose burned and melted. That basically drained the brake fluid from the rear brake(s).

The issue is:

I have a broken bleeder screw in the rear left calliper.

2)Had anyone any success in removing (drilling/dremel/heat?) it and keeping the calliper in working condition?

I am trying to find a replacement but it will take some time with the availability here. In the meantime, to be able to move the car from my place to where I can do some maintenance (not far from home, not highway or downhill), I would like to have the rear brakes in a workable condition.

Additional to that:

After I get a new calliper:
3) Do I need to bleed the rear right calliper too?

4) What can be done to prevent breaking the bleeder screw on that rear right calliper?

5) What about the front brakes?

Thanks for your help!
lurtz JUN 15, 02:33 PM
I would personally complete a full flush of all of the fluid, especially if you have cracked open any of the lines, and if you cooked the brake fluid, it is worth it to get fresh fluid throughout the system.

The proper procedure for bleeding and flushing the brakes is to start from the wheel the furthest away from the Master Cylinder and work your way to the closest. This method ensures that you do not leave any air pockets that can migrate through the system.


I know of no way to bleed brakes from the banjo bolt. You can bleed the lines, but the caliper needs to be bleed as well. I would look into a good bleeder system to help, especially if you are doing this on your own. I picked up a pump style fluid extractor from harbor freight with a coupon for just $69, and it works wonders for bleeding brakes without help. Also, it is pneumatic but runs off a manual pump, so no electricity or noise. And once you buy it, you will find other uses.

https://www.harborfreight.c...gg_q=fluid+extractor


Also, if you have a partner helping you bleed the system when they pump the breaks while you open and close the valves, make sure they do not bottom out the pedal. This will cause you problems with the seals inside your master cylinder. The rod that is connected to your pedal will have a build-up of stuff (corrosion etc. ) where the natural limit or throw is. With the system cracked open, you will go past this build-up, and it may tear up the seals.

[This message has been edited by lurtz (edited 06-15-2020).]

creaky78 JUN 15, 03:30 PM
If the car has auto tranny and you don't need a working handbrake for vehicle inspection, you have the option of using front calipers on the rear.
dremu JUN 15, 06:41 PM
At absolute minimum you gotta bleed both rear corners, though again, given what your car has seen, doing all four would be prudent. Brake fluid is cheap as compared to crashing and damaging your car (or someone else's!) FWIW, The circuit goes from the master cylinder to the rear right, then tees across to the left. This means (contrary to most other cars and the manual), you start at the rear LEFT side and do right side second.

At the very least, use a hand vacuum pump. IIRC Princess Auto is y'all northerners version of Harbor Freight, so you want something like this

https://www.princessauto.co...test-kit/A-p8895062e

(I use the HF one https://www.harborfreight.c...pump-kit-63391.html for comparison.)

they're cheap and nasty as compared to e.g. the Mityvac brand name ones, but IMO are better than the two-man method.

And you gotta bleed at the END of the line, which at the caliper is the bleeder screw (it goes softline w/ banjo bolt ... piston ... bleeder screw.) Trying to bleed in the middle will just make you angry and never get the bubbles out.

You might get the bleeder screw out with more heat, penetrating oil and/or an extractor. These are fluted tapered things like a reverse drill bit... usually come as a set, but as an example, https://www.princessauto.co...xtractor/A-p8619439e I don't know if that's the size you need, but you get the idea.

Oh, and see my thread on tipping the car @ http://www.fiero.nl/forum/Forum2/HTML/143922.html Given that you've run the rear circuit dry, you'll likely need to do this too.

-- A

[This message has been edited by dremu (edited 06-15-2020).]

Mike in Sydney JUN 15, 09:56 PM
In answer to your questions, this is what I would do. Others may have different opinions.

1) Is possible to bleed the brakes by the banjo bolt?

No. As others have said you need to bleed from the bleeders on the calipers following the process left rear, right rear, right front, left front. (Patrick, ain't that right?)


2)Had anyone any success in removing (drilling/dremel/heat?) it and keeping the calliper in working condition?

I think some my have but I've never been successful. I always messed up the threads. I'm not sure if you can drill out the broken bleeder and tap the caliper for a new bleed nipple. I've heard of others putting in a helicoil but I don' know it they were successful. My suggestion: Buy re-manufactured calipers from the Fiero Store, etc. cc


3) After I get a new caliper, Do I need to bleed the rear right caliper too?

Not a bad idea if you can afford it


4) What can be done to prevent breaking the bleeder screw on that rear right calliper?
Don't over tighten-it? If you're trying to loosen an existing bleeder, try soaking the area around the bleeder with a few drops of brake fluid and tapping on the caliper like you would do to a frozen bolt. Let it set for a bit and repeat. If it doesn't loosen up you could try heating the caliper with a heat gun or torch. CAUTION: REMOVE THE CALIPER FROM THE CAR IF YOU ARE DOING THIS. IT SOUNDS LIKE YOU NEED TO REPLACE YOUR LINES SO CUTTING THE LINES SHOULDN'T PROVE TOO MUCH TROUBLE..

Also, think about speed bleeders to replace your existing bleed nipples. I've got them for my Fieros and motorcycles.


5) What about the front brakes?

Are they in similar shape to the rear. If so, do the same to them.

(BTW - Edited to correct bleed sequence. My wife always told me I don'r know my right from my left. LOL)

------------------
Mike in Sydney

[This message has been edited by Mike in Sydney (edited 06-16-2020).]

theogre JUN 15, 10:28 PM
1. Very likely when 1 rear cal is bad w/ Fiero and related... Both are bad and should replace both at same time.

2. Yes, you need to "flush out" the entire system. "Water" will flood the whole fluid load fast just from pulling from air if you left any small hole open overnight worse if left open for days.

For front need to have working bleeder plus need to compress the pistons to minimize fluid space on them.
If slidders etc are good, doubtful, can compress front w/o taking everything apart. My guess the fronts need work too.

See my Cave, Brake Fluid and Brake Service
Expect to "eat" 1 or 2 litters of new fluid getting most old fluid out.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

Lambo nut JUN 15, 11:37 PM
I have had success bleeding via the banjo bolt but you can't do it while mounted on the vehicle. The caliper must be removed from the bracket and turned so the bolt is the highest point of the caliper while holding it.

And the bleed sequence for the Fiero is
Left rear
Right rear
Right front
Left front
theogre JUN 16, 11:12 AM
And every time the banjo bolts are loose/remove for any reason...
Need new "Crush Washer" for them.
Very Easy to Strip the caliper threads on most Aluminum caliper not just Fiero units.