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Hi,
since my abs pump is running every couple of minutes, i would like to replace the nitrogen accumulator. So, i suspect low pressure within the assembly and after 16 years i think that it might have drained over the years.
i already ordered the part from amayama and bought the o-ring as well.
now for the procedure...
-press brake pedal 40* so that pressure is as low as possible.
should i now drain the fluid with a syringe or open a brake line?
did someone already to this on a gs? do i have to remove the entire mbc? if i have to do so, i could also install new piston o-rings.
the manual is only giving the infos on a removed unit, not an installed one.
after installation, do i have to bleed brakes normally?
The real fix is just to replace the brake master cylinder unit
Its only like $7,000 for a new hydro unit if thats what you mean.
Originally Posted by brainsurge
-press brake pedal 40* so that pressure is as low as possible.
should i now drain the fluid with a syringe or open a brake line?
did someone already to this on a gs? do i have to remove the entire mbc? if i have to do so, i could also install new piston o-rings.
the manual is only giving the infos on a removed unit, not an installed one.
after installation, do i have to bleed brakes normally?
Press the brake pedal 40 times, don't bother draining the fluid. You don't have to remove the entire hydraulic brake booster but you can. You can unscrew the nitrogen accumulator from the top using a Toyota 4WD service tool P/N 09318-12010.
In order to change the piston o-rings, you will need to get a machine shop to mill the lip off thats sealing the top and bottom together. Before you do that, you will release the remaining pressure from the screw on the top of course. Then you will need to use a PTFE sealant to seal the two halves back together. You'll also need to install a 2,000 PSI schrader valve in order to recharge it with nitrogen to 1500 PSI.
You don't bleed this system like normal. What you're going to do is facing the brake booster, looking at it from the front of the car, you will bleed the left bleeder valve first by simply turning on the ignition and cracking the valve. You should have a hose attached to it to drain the fluid into a glass jar and watch for air bubbles. Let it run or repeat this procedure until no air bubbles come out and you see new brake fluid. Now do the same thing for the bleeder on the right side. You might have to actually move the pedal a bit to get it to pump. Now finally, bleed the master cylinder itself by cracking the bleeder valve on the front of it. You will need to pump the pedal for this part like bleeding a normal master cylinder.
Finally, you bleed the rest like a normal brake system starting with the wheel furthest away first.
This is from my experience on a JZS147 Aristo so yours might be slightly different.
Unfortunately the "bone yard" is not an option, since you won't find a lot of lexus there...i am in germany, not in the us. here it is called schrottplatz and there is only schrott ('scrap') on it (mostly vw, opel, mercedes, audi and this junk...
however, thank you very much for your explanation!
i am not fully sure if there is enough room over the mc for replacement of the accumulator in the car. i will show pictures, but at the moment i can't find a lot of time...
If you are replacing it, the 2001+ have better brake master cylinders, the bore plunger is larger so it pushes more brake fluid to the calipers for better brakes. You will need a huge 30mm socket as well for the sensor
I notice my brake pump comes on every second brake I step on, and I've just replaced the whole unit due to very soft pedal, so now I don't have soft pedal but this prob, just wonder can the op list the part number for the nitrogen canister and what's the cost of it? Also I thought this is a screw off screw on job, no machining involved?
Hi,
since my abs pump is running every couple of minutes, i would like to replace the nitrogen accumulator. So, i suspect low pressure within the assembly and after 16 years i think that it might have drained over the years.
i already ordered the part from amayama and bought the o-ring as well.
now for the procedure...
-press brake pedal 40* so that pressure is as low as possible.
should i now drain the fluid with a syringe or open a brake line?
did someone already to this on a gs? do i have to remove the entire mbc? if i have to do so, i could also install new piston o-rings.
the manual is only giving the infos on a removed unit, not an installed one.
after installation, do i have to bleed brakes normally?
If you are replacing it, the 2001+ have better brake master cylinders, the bore plunger is larger so it pushes more brake fluid to the calipers for better brakes. You will need a huge 30mm socket as well for the sensor
Has the bore been verified? The 98-01' use the same master cylinder pn and 98'-00' use the same piston seal kit part number. From 01' on the seal kits are the same. Something changed but if the bore did the seal kit from the 04' would not fit the 01' which uses the same master part number as the 98''. Also a larger MC bore does not give "better brakes", it will give a harder pedal if the caliper piston area is the same. Not trying to nit pick but there is a lot of mis info out there when people like me search a MC swap.
A 98' GS400 MC is 47025-30160 seal kit 04493-30280
01' GS430 MC is 47025-30160, seal kit 04493-30330
04' GS430 MC is 47025-30220, seal kits 04493-30330
RING, O NO.1 90301-08006 (the round-section black one)
RING, O NO.2 90562-09006 (the square-section white one)
You need two of one type and one of the other, however i am not sure at the moment which one you would need twice.
So, i still haven't done the replacement and i am still hesitating. however, since winter is coming, i'd rather do it before it gets cold outside.
I am still not sure how to exactly proceed, and if the removal can be done with the mc in place, also which steps are required after successful reinstallation of the new accumulator.
Is a normal bleeding of the brake system enough or do i have to bleed the lines on the mc first, before i drain the brake lines entirely?
06-11-17, 08:05 AM
GS 430 Nitrogen Accumulator Replacement
