Xylophone

Just got a new GS400 a week ago, and I took it to my mechanic after it failed the safety part of NYS Inspection from frozen rear calipers according to the shop that did the inspection. Got new rotors on all four corners, rebuilt rear calipers (one leaked, getting that changed), and new pads. Brake pedal was really soft so I also got 3qts of Valvoline Synth Brake Fluid to flush it (1-2 inches from floor fully depressed, had a good 1-2in of travel before actually having pressure). I know the PO already put on steel braided brake lines (what's the lifespan on them?), so I have a feeling he did not flush the fluid properly or it simply deteriorated somehow (car was driven 4k miles in 9 years).

I forgot to tell my mechanic the proper way to check fluid level in this car is to pump the brake pedal with the car off 40 times, and he overfilled the reservoir while bleeding the brakes. Will this cause any issues? I'll have him drain some out before the car officially goes on the road since I still have to get one caliper changed out and he'll need to bleed the brakes again. I'm mostly worried about anything happening to the Brake Master Cylinder/Brake Booster since they go for good money when they die.

GS4_Fiend

iTrader: (22)

I don't think so besides brake fluid all over the reservoir. Just simply clean it.

Xylophone

Will do, thanks. By the way, what could cause such a low pedal? I'm really hoping it'll get better once I finish getting the brakes bled, but its only a inch off the floor fully depressed and has a good two inches of travel before you feel any pressure, like its only activating the brake light switch.

FrankT

You can adjust the push rod at the pedal.
Get down there and have a look, you will see the push rod adjustment.

porn-adkt

iTrader: (37)

NOoooo....Tell me you flushed out the Old fluid from the Master, calipers lines,..The whole system before introducing the Synthetic....

Xylophone

I don't think he did, its DOT4 stuff I picked up at Autozone so it don't think it'll kill the seals either. I'll check the push rod adjustment, would it be at the MC or by the pedal?

Either way getting that stuff flushed out tomorrow. A rebuilt rear caliper ended up being leaky and I had to get it exchanged. By the way, is it ok to mix and match rebuilders for rebuilt stuff? One of the calipers I got originally was a King Kaliper from AutoBarn but the one coming in tomorrow is a A1 Cardone one after they ran out of the King Kalipers and wouldn't have a new shipment until a week from now earliest. I don't trust Cardone but I figure if the "good" rebuilt brand came defective I'll take my chances.

porn-adkt

iTrader: (37)

Synthetic will react with non Synthetic fluid causing some WEIRD SCIENCE EXPERIMENT.

Get it out ASAP.. stay with DOT 3. No need to upgrade the fluid on a stock system, just keep it fresh every 6 months or so.

This is a very expensive mistake as it can destroy your MC.

If you need a rear caliper swing by NY 10707.. you can have my rears for free.

iRyan

iTrader: (7)

All you need to do is open it press the brak let it leak out and clean it up....and move on wit life

Xylophone

Well I hope nothing happens, it claims it "mixes well with conventional fluids" and its rated as DOT 3/4. I upgraded because of the higher boiling point, and because the old fluid was brown and probably contaminated.

http://www.valvoline.com/products/co...brake-fluid/28

And thanks for the offer, but I already paid for the rear calipers and one of them is already on the car. I'm not that far in Queens.

porn-adkt

iTrader: (37)

Just trying to help you out from experience.. I could careless about labels. Synthetic DOES NOT mix with non Synthetic...you MUST FLUSH before introducing Synthetic into the system. Either way its your car. good luck..
Im Audi...... its getting past my bed time..We old Folk cant function like we used to in the cold

99 GS3

iTrader: (14)

The pedal engagement distance could be from the system still not being fully blead properly. There is an adjustment behind the pedal which adjust the freeplay but if the brakes worked fine before the fluid/caliper change then it should not be the issue. 2" is alot of travel. Because of the abs system the rears get blead a bit different than normal.

99 GS3

iTrader: (14)

If you haven't already checked this thread with bleeding procedure discussions, it may be of some help..

https://www.clublexus.com/forums/gs-...nder-99-a.html

GS4_Fiend

iTrader: (22)

This is the one I'm using, still working fine. The problem with our cars is when you bleed it, you gotta bleed it many times. As in dont just assume fluid is clean and no air bubbles coming and your good. No, do it like 1-2 more times to get that firm feel. I notice that from experience when I did mines. Air tight and firm brake pedal feel, not spongy.

Xylophone

I'll check the freeplay adjustment since the brakes were always very soft, just thought it was a Lexus trait at first.

The link helps, answered my question about what would happen if you overfilled the reservoir (fluid would just overflow under the cap) and it does clarify on how to bleed it (pump brakes 40 times with car on, then key off and bleed) but it was a bit confusing with order to bleed brakes. Seems like the FSM according to one guy says to do the fronts first, but others in the thread did the rears like you would on most cars without issues.

I did notice some people mention that you needed a special Toyota tool to bleed the MC, but I do remember in another thread one guy whose mechanic just took the car to speed and slammed the brakes to activate ABS or something along those lines to move the fluid.

Between having to pump the brakes 40 times before bleeding and having to do it 1-2 more times...seems like bleeding brakes on these cars is a day long affair.

GS4_Fiend

iTrader: (22)

TBH, I didn't pump the brakes 40 times. First, I suck all the fluid out from the BMC then add new fluid. Then key on engine off, one guy open the bleeder valve right rear, and one guy holding on the brakes and as soon as fluid goes low, refill. I did it about 3 times, but that's just me. Then did the left rear same procedure. Then the right front, key off. Pump brakes 3-5 times and then bleed. I did it 3 times. Then last the left front same procedure. After that, i filled the reservoir about half way closed the lid, went inside and pump 40 times and check the reservoir and refill if necessary. And thats it. It worked for me and brakes still working properly till this day. And I used the Valvoline Synthetic DOT3/4. Won't need to change it for a while.