socalturbo

Hi Everyone,

Is there a write up on how to change the brake fluid or is it the typical pump, hold, then open and close the valve on the caliper from farthest to closest? Also, is it ok to use dot4 super blue fluid and do we have a vendor that sells SS Brake lines?

Thanks in advance.

kuWuPt

iTrader: (13)

start from rear passenger, then rear driver, the front passenger, then the front driver corner.

for the rears, turn ignition ON, car doesnt have to be running. 1 person press the brake pedal and the other can bleed. You only need to pump and hold once. When clean liquid is coming out of the bleed valve (clear hose attached to it) bleed valve can be closed. Same on the driver rear.

for the front, engine has to be off and key out of ignition, pump the brakes 3 to 5 times, then hold steady pressure on the brake pedal. other person opens the bleeder screw until the brake pedal hits the floor, close the bleeder screw and repeat process until fluid is clear, and no air bubbles. same for the other side.

socalturbo

thanks for the info. Anyone here using dot4 fluid?

Caseoane

I use dot4. No issues.

jzwu

Don't mix DOT 4 with DOT 3 fluid. The stock fluid is DOT 3. You can use DOT 4 but flush the whole system first.

kjcole

You must be thinking of DOT 5, which can't be mixed with DOT 3 or 4 because it is silicone based). I copied the following from a different forum, and what this person wrote is consistent with my understanding. I've been adding DOT 4 to DOT 3 stock systems for years, including high performance motorcycles:

"DOT4 and DOT3 are both polyethylene glycol based, which is a synthetic polymer....DOT4 increases the boiling point over DOT3 by adding borate esters. That's it. DOT4 is cheap to produce, so fluids with DOT3 maximum performance don't make much sense. Some manufacturers have resorted to just packing DOT4 into bottles marked DOT3/DOT4 so the target market will not ask questions.

What is important, however, and was mentioned before, is care in handling PEG based brake fluids (everything but the silicone DOT5). Always use new bottles, because the oil immediately starts absorbing moisture, hence the requirement to change it every year or two to maintain the boiling point."

V300Graham

I'm using DOT 5.1 which is backward compatible with DOT 3 and 4. Never use DOT 5. It a different composition and us basically for racing cars. It produces a fairly soft pedal as well. DOT 5.1 is regular brake fluid. I'm running it for 2 years with zero problems.

momssc

Why key on and one pump for the rear?

kuWuPt

iTrader: (13)

The ABS pump works in transferring the fluid to the rear. Because of the long lines the ABS does the pumping for you. I'm no expert though, a couple of Toyota techs told me about this back in the day and that's how I have been doing it. You can do it the the tried and true method of pumping it multiple times and holding and bleeding with the car off and key out of the ignition too.

momssc

I thought the ABS pump only activated when a wheel locked up.IDK

gripau1

Yes this is the correct way to bleed the rear brake lines.
Make sure the brake reservoir is full of fresh brake fluid when you are doing the rears as the accumulator pump will squirt out alot of brake fluid.

Also try to suck out / remove the the old fluid from the brake reservoir before you start bleeding the brakes. You don't want dirt and crap passing through and ripping up the seals and stuffing up the ABS module.

As a side note, the SC430 originally came with DOT 3, even though DOT 4 is compatible with DOT3 I personally would stick with Toyota DOT3 if you are planning to keep the car for a LONG time. What I've seen from experience is that DOT4 tends to swell up the rubber seals and brake lines.

I've seen this happen with Soarers of the same vintage 1991, one using DOT 3 and the other using DOT 4. The Soarer with always using DOT 3 (mine) has more km approx (120k km) more than the other Soarer with DOT 4. The ones with DOT 4 required new brake lines and the master cylinder seal was leaking. We are talking a 20 year old car here. So maybe over long period of time there is a difference in properties between DOT 3 and DOT4.

My Soarer brakes fuilds were changed every 20k km or 1 to 1.5 years and did about 500k km before it went to Soarer heaven thanks to a taxi.

jzwu

Right. DOT 4 is high performance, i.e., higher boiling point. But it absorbs water more easily too, not good for brake line and seals unless it is flushed regularly.