Just picked up a '91 RRC last week. It had been sitting for 2yrs. The only thing wrong is the brakes. Hard pedal and ABS pump continuously runs. Took old pump out and installing new/used pump. After installing pump do you have to bleed the entire brake system? I here it is a nightmare!
RRC brake bleed after new pump?
- Thread starter dlittle
- Start date
You should bleed it regardless of swapping the pump out, after two years. Good to get fresh fluid in the system, be sure you use the right stuff.
Did you check the pressure switch first? A good pump running constantly because of a bad Px switch would give a hard pedal I believe.
Did you check the pressure switch first? A good pump running constantly because of a bad Px switch would give a hard pedal I believe.
Did not check pressure switch. Were is it? Have new/used relays also to install. Can't find Castrol brake fluid. What is a good second choice? I got a parts truck with purchase of running Rover so getting most parts from it.
Is your parts truck white?
The switch is on the pump. DOT 4 is the brake fluid spec isn't it?
Make sure you clean up after the system bleed procedure. I had one erupt in flames in my garage once. Nasty old brake fluid had got onto the exhaust. Started smoking, thought it would burn off without being a problem... and it didn't
The switch is on the pump. DOT 4 is the brake fluid spec isn't it?
Make sure you clean up after the system bleed procedure. I had one erupt in flames in my garage once. Nasty old brake fluid had got onto the exhaust. Started smoking, thought it would burn off without being a problem... and it didn't
ptschram
Well-known member
The most common reason for an ABS pump to run on is the accumulator, not the pressure switch. I [personally have yet to see a bad pressure switch and have only heard of one person who did and it turned out to be the accumulator.
ptschram
Well-known member
The switch is difficult to test as it is difficult to measure brake fluid pressure without going to extreme lengths. Bear in mind the pressure generated by the pump exceed 2000 PSI, take suitable precautions.
I either have in stock new or sued parts for ABS systems or can get them easily enough.
I either have in stock new or sued parts for ABS systems or can get them easily enough.
ptschram
Well-known member
As for bleeding, it is not uncommon to swap out pumps/accumulators and not need to bleed the brakes. I suspect that degree of pressure exerted by the pump forces the air to the top.
If it is necessary, it's the easiest Rover there is to bleed as the pump provides plenty of pressure.
If it is necessary, it's the easiest Rover there is to bleed as the pump provides plenty of pressure.
most common reason imo for the pump to run constantly is a stuck relay. a bad accumulator will just make the pump run with every press of the pedal instead of every 3-4.
ptschram
Well-known member
Good point, as likely a cause as any and as we have nothing more to go on other than an incessantly running pump,it could be a worn out pump, stuck relay, bad pressure switch (although unplugging the switch ought to reveal this as the culprit), or accumulator.
Given the fact that the youngest RRC is now 25 years old, it could be any of those or all of them.
Put new/used pump in today. Bled the the entire system since it had sat for two years. Followed the RAV. It went well thanks to my 14yr old son. A bit time consuming but it worked. Drove for a couple of miles and felt good. Let it set for an hour then drove some more and brake light came back on. But everything seems to be working. Not sure what else to do other than bleed system again. Thanks again for all the info/help.
Your math is off, PT! 27 years for the oldest NAS RRCs (1987), 19 years for the last NAS RRC (1995).
ptschram
Well-known member
Your math is off, PT! 27 years for the oldest NAS RRCs (1987), 19 years for the last NAS RRC (1995).
That was the model year. Production ended in late '94 or early '95.
As for the lite being back on, top up the reservoir.
PT, when is it recommended to change the accumulator ?
I'm ressurecting my LWB Tdi now, and have never touched the accumulator.
Brakes are fine other than the pedal not returning all the way; making the lights stay on.
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I replaced mine when the diaphragm broke and it swallowed all the fluid in the master cylinder. If you have the system open for pump or master cylinder , it's reasonably cheap to replace.
if the pump comes on sooner than 3 solid presses of the pedal then the accumulator is bad. Another leak people commonly miss is the rear brake proportioning valve. Its either on top of the ABS valve body or down on the inner fender well.
Thanks-I'll check that out. I havent noticed the pump coming on excessively but I will try the 3 presses deal.
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Since this seems a good live thread on RRC brakes....
Does anyone know what would cause my pedal to "push back" every so often when first pressed? Feels like its alive. Ha ha
Brakes work well, feel good etc - but sometimes when it does the "push back" thing the truck may pull a little to the right.
Ideas? Thanks.
Does anyone know what would cause my pedal to "push back" every so often when first pressed? Feels like its alive. Ha ha
Brakes work well, feel good etc - but sometimes when it does the "push back" thing the truck may pull a little to the right.
Ideas? Thanks.
I thought that was the ABS kicking in. Seems I had something like that once and was told to clean and reseat the front ABS sensors.