whats wrong with my brakes
09-15-2007, 10:53 PM
#16
Chronic Tool Dropper
Lifetime Rennlist
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Lifetime Rennlist
Member
Symptoms say master cylinder. A good flush/bleed **might** cure the symptoms for a while, but they will likely return. Never at an opportune moment either, since you only have the problem when you need the car to slow down NOW.
dr's advice: Replace the master cylinder now, and be done with it. The flush/bleed effort is the same whether you do it with an old or new cylinder, except you only need to do it once with the new cylinder. It takes longer to jack the car up for the bleed/flush than it does to change the master cylinder. Order the pressure bleeder if you can't borrow one locally. Get new grommets for the reservoir if they aren't included, and maybe a pretty new non-yellowed reservoir at the same time.
On the fluid, Castrol LMA is DOT-4 and very suitable for street-driven cars. It's also widely available at local auto parts stores. The ATE blue or gold fluid is good too, and makes it a little easier to see when your flush is done next time. Specs are a little better than the Castrol but IMHO not enough to get excited about in a street car. The best specs for non-silicone fluid are coming with others now, like the Motul fluids. You can usually find them at better motorcycle places and on line. If you don't track the car though, don't waste your money-- the Motul recommendation is flush/replace every six months to keep the temp ratings. Gets expensive and time consuming in a hurry. Get the Castrol LMA and you'll be fine.
dr's advice: Replace the master cylinder now, and be done with it. The flush/bleed effort is the same whether you do it with an old or new cylinder, except you only need to do it once with the new cylinder. It takes longer to jack the car up for the bleed/flush than it does to change the master cylinder. Order the pressure bleeder if you can't borrow one locally. Get new grommets for the reservoir if they aren't included, and maybe a pretty new non-yellowed reservoir at the same time.
On the fluid, Castrol LMA is DOT-4 and very suitable for street-driven cars. It's also widely available at local auto parts stores. The ATE blue or gold fluid is good too, and makes it a little easier to see when your flush is done next time. Specs are a little better than the Castrol but IMHO not enough to get excited about in a street car. The best specs for non-silicone fluid are coming with others now, like the Motul fluids. You can usually find them at better motorcycle places and on line. If you don't track the car though, don't waste your money-- the Motul recommendation is flush/replace every six months to keep the temp ratings. Gets expensive and time consuming in a hurry. Get the Castrol LMA and you'll be fine.
09-15-2007, 11:41 PM
#17
Team Owner
If you do replace the master cyl you can clean out the old resivour with some brake cleaner followed by a wash with some simple green and hot water then a few rinses with isopropil alcohol followed with a air dry with a hand held blow drier, this will return your yellowed resivour to like new condition to remove the res from the master cyl just tilt it side to side a few times as you gently lift it up keep a few rags under the res so any fluid will fall into the rags, use a cover over your fender while working on the car
09-17-2007, 03:48 PM
#20
Burning Brakes
Had the exact same problem, bleeding did nothing and I got tired of driving the car W/ the brakes this way. Comming up to a stop and using the "double pump and pray" method got me to just go and do the brake master replacement and be done W/ it. Good advise from dr bob and Mrmerlin.
