Brake failure
#1
Brake failure
Yesterday, while on the road my brakes got softer and softer and ultimately I could not stop on time for a 4-way-stop as the brake pedal went to the metal. Only after pumping 3 times or more would it still brake a bit. Driving about 15 - 20 mph, and having my surprisingly useless handbrake ready (new pads), I made it home. I checked the break reservoir: there were small particles on the filter, but otherwise it was full. There was no puddle of oil. I ordered a new reservoir and brake master cylinder. So I will put those on first. I think it would be wise to drain the system first.
The question is, how do I drain the brake/steering system to replace the fluid?
Thanks!
The question is, how do I drain the brake/steering system to replace the fluid?
Thanks!
#2
Join Date: Mar 2008
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There is no drain, per se, for the brake system. The reservoir and master cylinder can be emptied when you remove them. The remaining fluid in the system is pushed out during the brake bleeding process.
Cheers
DD
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#3
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Don B (05-01-2024),
Greg in France (05-01-2024)
#4
daanv,
What makes you think it needs a new master cylinder? As you mentioned that the car had been laid up for some time, there could be a number of reasons for a soft pedal, including air in the system, absorption of water in old fluid, even a leak somewhere.
I definitely wouldn't fit anew m/c yet. I would do a full flush of the system first, then check the state of the calipers and brake lines. I'd also probably replace the flexis as well.
Good luck
Paul
What makes you think it needs a new master cylinder? As you mentioned that the car had been laid up for some time, there could be a number of reasons for a soft pedal, including air in the system, absorption of water in old fluid, even a leak somewhere.
I definitely wouldn't fit anew m/c yet. I would do a full flush of the system first, then check the state of the calipers and brake lines. I'd also probably replace the flexis as well.
Good luck
Paul
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Don B (05-01-2024)
#5
#6
Assuming a non ABS car, it definitely needs a new M/C! Make sure you fit the new one, say I.
If you do, it can be difficult ot get the fluid primed and pumping through it properly. What I do is to connect up the new one to the reservoir, but do not connect the outlets to the two pipes to the calipers. Then fill the reservoir and get someone to pump the pedal to order. Ask the helper to push the pedal down and hold it down, then place a finger over each outlet and ask the helper to release the pedal. Repeat a few times until fluid pumps out and then connect the pipes. This procedure prevents the new M/C pulling air back into itself rather than fluid from the reservoir. Place some rags under the M/C to ensure no fluid spills onto the bodywork.
When bleeding, start with the rear opposite corner and pump through until new bubble free fluid comes out. Then the other rear caliper, then the front opposite and finally the one nearest the M/C. You have inboard brakes and the rear nipples are difficult to get at.
Excuse my making this point if you already know, but if you have never bled brakes before, it is best with two people, one on the pedal and the other under the car doing the nipple. Make sure you can loosen the nipple and attach a piece of clear plastic pipe to it, make a loop in the pipe with the free end into a container. The purpose of the loop is so you can see bubbles or not in the fluid coming out. Your helper presses the pedal to order AND HOLDS IT DOWN while you simultaneously loosen the nipple just enough for fluid to come out. Do up nipple and only then tell helper to release the pedal. Keep repeating until clear bubble-free fluid comes out. BUT ensure the reservoir does not run out of fluid, so regular topping up and checkin,g mlevel is vital.
The bleed nipples can be very hard to loosen, make 100% sure you have a small ring spanner of the correct size.
If you do, it can be difficult ot get the fluid primed and pumping through it properly. What I do is to connect up the new one to the reservoir, but do not connect the outlets to the two pipes to the calipers. Then fill the reservoir and get someone to pump the pedal to order. Ask the helper to push the pedal down and hold it down, then place a finger over each outlet and ask the helper to release the pedal. Repeat a few times until fluid pumps out and then connect the pipes. This procedure prevents the new M/C pulling air back into itself rather than fluid from the reservoir. Place some rags under the M/C to ensure no fluid spills onto the bodywork.
When bleeding, start with the rear opposite corner and pump through until new bubble free fluid comes out. Then the other rear caliper, then the front opposite and finally the one nearest the M/C. You have inboard brakes and the rear nipples are difficult to get at.
Excuse my making this point if you already know, but if you have never bled brakes before, it is best with two people, one on the pedal and the other under the car doing the nipple. Make sure you can loosen the nipple and attach a piece of clear plastic pipe to it, make a loop in the pipe with the free end into a container. The purpose of the loop is so you can see bubbles or not in the fluid coming out. Your helper presses the pedal to order AND HOLDS IT DOWN while you simultaneously loosen the nipple just enough for fluid to come out. Do up nipple and only then tell helper to release the pedal. Keep repeating until clear bubble-free fluid comes out. BUT ensure the reservoir does not run out of fluid, so regular topping up and checkin,g mlevel is vital.
The bleed nipples can be very hard to loosen, make 100% sure you have a small ring spanner of the correct size.
Last edited by Greg in France; 05-01-2024 at 11:15 AM.
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JJS- Florida (05-02-2024)
#7
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#8
All of which means the M/C rubbers will be toast Paul!
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ptjs1 (05-01-2024)
#9
#10
I was referring to the rubber seals inside the M/C. These will be already inside the new one, so no worries!
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orangeblossom (05-01-2024)
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