rmjsupra;1378392 said:
There is a need for DOT 4, as every set of steel braided lines I've seen specifies using it. I use it in mine. Dot 5 however, is not to be used with ABS systems.
ARZ BBK customers, chime in please
- Thread starter Boosted Supra
- Start date
There is a need for DOT 4, as every set of steel braided lines I've seen specifies using it. I use it in mine. Dot 5 however, is not to be used with ABS systems.
I've had zero problems with my 4-piston wilwoods. Even when I had a ton of air in my system, I didn't need to pump the pedal before the power would come on. Start with the MC test and go from there.
DOT 3 and DOT 4 are similar hydroscopic fluids (absorb moisture). Steel braided line is nothing more than a rubber brake line hose wrapped and a steel braiding, so it should not matter if DOT 3 or 4 is use.
I know for a fact from a very reliable source the Wilwood recommend either DOT 3 or 4 in their systems. The Wilwood 570 brake fluid is a DOT 3 and the Wilwood 600 brake fluid is a DOT 4.
DOT 4 is better and yes it is what I use as well, I actually run the Wilwood EXP 600 on my daily.
The Silicone in the DOT 5 makes the fluid non hydroscopic and the fluid needs to be changed regularly, not doing this will cause you to have moisture build up seperately from the brake fluid (oil is heavier that water and DOT 5 does not absorb water). Only real benefit to DOT 5 is that it will not ruin paint.
Most of the top performing high temp brake fluid out there is a form of DOT 4.
I know for a fact from a very reliable source the Wilwood recommend either DOT 3 or 4 in their systems. The Wilwood 570 brake fluid is a DOT 3 and the Wilwood 600 brake fluid is a DOT 4.
DOT 4 is better and yes it is what I use as well, I actually run the Wilwood EXP 600 on my daily.
The Silicone in the DOT 5 makes the fluid non hydroscopic and the fluid needs to be changed regularly, not doing this will cause you to have moisture build up seperately from the brake fluid (oil is heavier that water and DOT 5 does not absorb water). Only real benefit to DOT 5 is that it will not ruin paint.
Most of the top performing high temp brake fluid out there is a form of DOT 4.
Gotta find the article, but DOT5 doesn't like vibration and as such DOT4 is far safer...
Also, your master cylinder could be completely fubar but you'll never know until you pop it loose from the brake booster as there is a seal and no weep hole to allow the fluid to escape (until it destroys the seal on the brake booster and starts going into the engine).
Also, your master cylinder could be completely fubar but you'll never know until you pop it loose from the brake booster as there is a seal and no weep hole to allow the fluid to escape (until it destroys the seal on the brake booster and starts going into the engine).
Did the Brake MC test, pumped for about 5-10 times and is doesn't really get firm, it's stiff but not as I would have expected. Pedal drops 1/4 of the way, maybe even 1/2 way.
I also checked the pads, it seems a bit low. Pads were never replaced since I installed them back in 2003 (hardly drove the car).
Looks like I need a new MC and a new set of pads.
Do I need to replace brake booster as well?
I also checked the pads, it seems a bit low. Pads were never replaced since I installed them back in 2003 (hardly drove the car).
Looks like I need a new MC and a new set of pads.
Do I need to replace brake booster as well?
rmjsupra;1378714 said:
This I know, nonetheless, every set of Steel Braided hoses I've seen, has recommended using Dot 4. Also many brands use teflon and kevlar, not just plain rubber.
or just let the car sit for 10 mins and pull the line to the booster....it should still be under vacuum thanks to the check valve.
Found the correct specs (I had a picture of my wilwoods unmounted), sorry for the confusion guys.
1.75" 44,5 mm 1.25" 31,8 120-7429-R/L
1.75" 44,5 mm 1.25" 31,8 120-7429-R/L
adampecush;1378849 said:
Yes, but that won't spot a small leak as you won't have a gauge. Easy to rent a gauge, suck it down, and then let it sit for a few hours and see if it's moved.
Have you always had this problem or just recently? If only recently, or slowly increasing over time (and you confirmed your pads are low) sounds like you need new pads. Change those first (easiest and needed anyways) and inspect the calipers and pistons and brake lines. If the problem persists test your MC per the manual.
BTW what rear calipers do you have?
BTW what rear calipers do you have?
You can buy a vacuum gun/gauge at Harbor Freight for like 15 bucks, always good to have one around.
Boosted Supra;1378817 said:
You only need to pump it to exhaust the booster vacuum, if it creeps towards the floor at all over time while holding firm pressure you have a leaking MC so time for a new one as it's letting air in on it's return stroke and explains your long pedal.
bfr1992t;1378934 said:
I'm actually going to replace the brake MC cause I believe it's original (20 yrs old). I also purchased some new pads.
I have stock rebuilt calipers in the rear
Good news.
After replacing my tired 20 year old brake master cylinder and upgrading to DOT4 brake fluid. I can honestly say that my brakes are extremely good. The thing stops on a dime and I've never felt so safe when braking. The braking power is amazing and NO pumping of brakes is required; I'm loving my supra even more.
I let Howard H drive my car to experience the braking power, he was impressed. I'll let him chime in to give you his thoughts.
So all you Jim King BBK owners, replace your old BMC and bleed until it's perfect.
Thanks to Brian@ BD performance
Thanks to wilwood for the exceptional advice, and everyone else.
After replacing my tired 20 year old brake master cylinder and upgrading to DOT4 brake fluid. I can honestly say that my brakes are extremely good. The thing stops on a dime and I've never felt so safe when braking. The braking power is amazing and NO pumping of brakes is required; I'm loving my supra even more.
I let Howard H drive my car to experience the braking power, he was impressed. I'll let him chime in to give you his thoughts.
So all you Jim King BBK owners, replace your old BMC and bleed until it's perfect.
Thanks to Brian@ BD performance
Thanks to wilwood for the exceptional advice, and everyone else.
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Those calipers will definitely NOT work on the front of a MKIII just so no one gets any wise ideas.Boosted Supra;1378003 said:
This was my first thought too. Especially you new brake installers, since they all just got done cracking the system I always cover proper bleed techniques with them (farthest, to nearest, then inboard to outboard on each caliper). If they still have issues, then make sure to check the runout and make sure the mounting surface is VERY clean and flat, and not dinged.IJ.;1378056 said:
Dont upgrade your fluid just for the hell of it. Make sure the fluids are compatable, swapping fluid in some directions will swell ever seal in your brake system and you will be in for a lot of work.Boosted Supra;1378375 said:
Yea if it moved at all you have a leak somewhere. Glad to hear you found it.Boosted Supra;1378817 said:
Yea that's the same one I use for my 4 piston.Boosted Supra;1378862 said:
Again glad to hear you found your problem and solved it.
I have and a few of my customers experience similar problems and it was always due to them not cleaning the hub surface or some piece of debris. Once I accidentally fastened a small chip between the rotor hat and the rotor. Now I make every effort to make sure that interface is perfect.