Ok, title is rather self explanatory. Today my brother and I flushed the brakes on my '93 (LHD, US Spec, 4.0). I had him turn the ignition on and hold the pedal and used the pump to push the fluid through. That seemed to work, though don’t know if it was working properly. As soon as he turned the key on the motor would start running for about 20 seconds then stop. Then as soon as he pushed the pedal it would start running again. I don’t know if that’s how the pump should work or not, but it got good fresh fluid to the rear brakes.
On to the front brakes and theres an issue. We lift the front right wheel and we cannot turn it to save our lives. Get the wheel off and take the caliper off. I opened the bleeder and tried to push the piston in. It does go in. Put the caliper back together. We try bleeding it 2 different ways. We try the standard pump and hold method (both with key on and key off), and we try pulling fluid through with a vacuum pump… No matter what we try, we cannot bleed the front right.
So we move on to the left. That wheel spins freely. We do pump and hold and I get a big squirt from the bleeder… then nothing else. Again we even try pulling fluid through with the vacuum pump and there is NO fluid coming through.
At this point in time I’ve figured the calipers are probably bad, so I just put the wheels on and decide to CAREFULLY back it into it’s spot… The brake pedal goes straight to the floor. It’s like the rear brakes aren’t doing anything. I throw it in neutral and it gently rolls to a stop in its spot.
So does this sound like the calipers are bad, or the abs module, or the accumulator bulb. The car is so close to being road ready, but the lack of brakes is extremely alarming.
The front brakes are bled differently to the rear. Use the old method of opening the bleed screw, depress the pedal, close the bleed screw, release pedal. Don’t use the ignition.
We tried bleeding it the conventional way and no matter what I could not get any fluid to come out of the front calipers. Even when we tried pulling the fluid through using a vacuum pump. I’m wondering if the ABS valves are stuck or bad.
Do you know whether the front brake lines are original to the car? How about the rear lines? Brake lines have been known to break down internally and prevent the free flow of fluid.
I don’t. The rears gave me a nice steady stream of fluid which allowed me to get the old fluid out. When I got to the front right, I couldn’t turn the wheel to save my life. When I opened the bleeder it gave a jet of fluid, the wheel started to turn, but got no more fluid. Then when I went to the left side the wheel spun but again when I opened the bleeder got one initial shot and no more. I’ll have to look through the service records that came with it to see if the brake hoses have ever been replaced.
Try undoing the connection to the flexible hose inside the wheel arch then get your friend to press the pedal. If fluid squirts out the metal brake pipe this will tell you the problem is downstream from this, ie in the caliper or the flexible hose itself, sometimes the hose can collapse internally but it would be unusual for that to happen on both at the same time.
1__ with pump pressurizing the high pressure brake systems brake fluid, it was probably not necessary to pump the pedal. Considering that the pump puts out 100’s of PSI maybe more… you and the PUMP may have added too much high pressure working together… there is no way you will relieve all that high pressure with measly bleed screw (especially if it is clogged) and therefore you slammed the calipers pistons locked onto the rotor disks and yes if old calipers possibly not used in a while and or possible piston has some minor corrosion causing friction on the piston it will lock and not easily retract…and hold the brakes rotors like you experienced…
I would be very surprised if the rubber hose clogged Ive seen many a cracked rubber hose but none that were clogged… more likely you did not get any fluid out because the bleed nipple is clogged or calipers bleed hole at bottom of bleed nipple is clogged—. Remove bleed nipples on suspect calipers and and if fluid starts to come out of hose–a good sign— then id temporarily plug the hose remove the nipple and examine the nipples bleed hole-blow through it—… also see of you can gently poke something into the calipers bleed hole at bottom of bleed nipple— should be open and clear—… but may be dirt or corrosion (bad sign) blocking the flow on you.
Put some dot 4 fluid (never use silicon in ABS brakes as pulsation aerates it) in same brake fluid just distilled more with more water removed and has higher boiling point…
Good luck
B
Another tip when dealing with ABS brakes: When replacing pads, always open the bleed screw when pressing the caliper piston back into the caliper. This prevents possibly contaminated, and dirty fluid being pushed back into the very intricate and delicate ABS valve body. From my Jaguar warranty experience when ABS was first introduced we had many cases that after a brake job the car would pull left or right when braking. Because the above procedure had not been used we suspected contamination had caused one or more valves in the ABS to stick or not properly close. I also believe that for cars operated in areas where the ABS never actually comes into operation (dry climates, no ice or snow) it is a good idea to exercise the system once in a while on a wide open gravel road and make all the valves actually operate. And lastly, a flush with fresh fluid about every 3 years is a good maintenance practice,
