When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Purchased OEM master cylinder rebuild kit and related parts.
20 years is a long time for rubber seals sliding back and forth in a cylinder immersed in brake fluid.
All cylinder seals appeared in serviceable condition with slight wear and visible crusting on the rubber surface.
Original cylinder spring.tension. was slightly softer than replacements..but expected after 20 years in compression. Did not like that spring ends were square cut instead of beveled flush as are valve springs...so side movement was observed when compressing old springs.
Few images were taken of extraction or disassembly on account of minding messy brake fluid that likes to eat paint, including on cell phones.
The master cylinder employs two metal pins to retain the pistons within the cylinder. - center holes. By holding the cylinder assembly upside down and inserting a rubber coated tool handle into the piston bore (next image) and compressomg the pistons, first one, and then second, both pins simply drop out with gravity. Use a rubber coated tool or risk gouging the bore. This end depicts piston installed in bore .notice the slots are aligned.. The innermost piston slot is indexed 90 degrees .New rubber collar seal installed. Images depict OEM part numbers used in rebuild. Toyota specifies "Rubber Grease" in the shop manual $12.. The old pistons shown here. Notice the long slots in the piston push rods provide clearance for retaining pins. I believe earlier models used retaining rings or e-clips to hold the pistons in place. Left the return hose connected to the reservoir , and instead disconnected it at the metal tube to avoid stressing or fracturing the plastic barb. The replacement shoulder screw is too short so will sort it out or reuse original shoulder screw. Notice original hardware used more durable mil spec zinc-dichromare plating while replacement hardware plating appears to be zinc...
I understand your position yodaone, and applaud your commitment to getting things done right the first time to the best quality.
I tend to weigh my options and value things accordingly.
if I don't have the expertise or the means to rebuild a MC, my only other choice outside of buying new is a reman'd part for this scenario.
of course safety is of utmost concern and the MC is a huge safety critical piece.
This forum is replete regarding issues with Autozone alternators, P.S. pumps, steering racks...etc.
It begs the question why anyone would risk their lives on an Autozone Master cylinder....rebuilt where and what parts?
Gee, Sorry, No...
The forum is also replete with barn finds and similar threads about mint, perfect old LS400's, asking for a good value estimate ... and the answer is around $2-3k. And most cars on here requiring repair do not qualify as mint condition.
It begs the question why anyone would exclusively advise to use genuine parts as if they are the only things that work. A $300 dealer part (no idea what it really costs - this is a general comment) is probably better than a $88 Autozone one, sure, but if the car is truly only worth $1500, is it reasonable to consider the $88 one? I think it is.
Also, brake components, by design due to their importance, tend to be fundamentally simpler and tougher to screw up than things like alternators and PS components. This means they should be easier for a DIYer to rebuild, and also easier for the third world rebuilding farms to do without problems.
Myself, my '91 is over 200k now, running great, looking not so great due to clearcoat and paint issues. I'll guess it's worth $2k to the rest of the world, more than that to me. For the specific problem discussed in this thread, I was able to rebuild the MC myself with the Lexus rebuild kit.
When I had a brake hose leak in this car a few years ago, I felt no fear in replacing all 4 hoses with new Dorman parts. And those 4 parts probably cost the same as a single Lexus/Toyota part. Which move do you think was safer, 4 new Dorman hoses, or one new Lexus hose?
The forum is also replete with barn finds and similar threads about mint, perfect old LS400's, asking for a good value estimate ... and the answer is around $2-3k. And most cars on here requiring repair do not qualify as mint condition.
It begs the question why anyone would exclusively advise to use genuine parts as if they are the only things that work. A $300 dealer part (no idea what it really costs - this is a general comment) is probably better than a $88 Autozone one, sure, but if the car is truly only worth $1500, is it reasonable to consider the $88 one? I think it is.
Also, brake components, by design due to their importance, tend to be fundamentally simpler and tougher to screw up than things like alternators and PS components. This means they should be easier for a DIYer to rebuild, and also easier for the third world rebuilding farms to do without problems.
Myself, my '91 is over 200k now, running great, looking not so great due to clearcoat and paint issues. I'll guess it's worth $2k to the rest of the world, more than that to me. For the specific problem discussed in this thread, I was able to rebuild the MC myself with the Lexus rebuild kit.
When I had a brake hose leak in this car a few years ago, I felt no fear in replacing all 4 hoses with new Dorman parts. And those 4 parts probably cost the same as a single Lexus/Toyota part. Which move do you think was safer, 4 new Dorman hoses, or one new Lexus hose?
Have spent time replacing low quality aftermarket parts installed by previous owner that have failed and posted differences;
Water pump, timing belt, upper and lower radiator hoses, P.S. pump, starter, alternator...
No one questions OEM quality...
OEM Master Cylinder rebuild parts with rubber grease cost me about $110 including tax.
Unsure where Dorman manufactures its parts...but highly unlikely it is Japan.
Purchased replacement front and rear flexible brake caliper hoses from Lexus.
The forum is also replete with barn finds and similar threads about mint, perfect old LS400's, asking for a good value estimate ... and the answer is around $2-3k. And most cars on here requiring repair do not qualify as mint condition.
It begs the question why anyone would exclusively advise to use genuine parts as if they are the only things that work. A $300 dealer part (no idea what it really costs - this is a general comment) is probably better than a $88 Autozone one, sure, but if the car is truly only worth $1500, is it reasonable to consider the $88 one? I think it is.
Also, brake components, by design due to their importance, tend to be fundamentally simpler and tougher to screw up than things like alternators and PS components. This means they should be easier for a DIYer to rebuild, and also easier for the third world rebuilding farms to do without problems.
Myself, my '91 is over 200k now, running great, looking not so great due to clearcoat and paint issues. I'll guess it's worth $2k to the rest of the world, more than that to me. For the specific problem discussed in this thread, I was able to rebuild the MC myself with the Lexus rebuild kit.
When I had a brake hose leak in this car a few years ago, I felt no fear in replacing all 4 hoses with new Dorman parts. And those 4 parts probably cost the same as a single Lexus/Toyota part. Which move do you think was safer, 4 new Dorman hoses, or one new Lexus hose?
Just finished bleeding the master cylinder, brake lines and antlock brake solenoid block.
Used two quarts to flush out all old fluid.
The pedal feels firmer with new master cylinder piston/seal assembly.
In order to fully and correctly bleed the system, a special.service tool is required for purging air from the anti-lock brake solenoid block.
It fits over the mouth of the brake fluid resorvoir and regulated pressurize air purges air from the system.
I also used it for one person bleeding...
Regulated air pressure imperative
Used 15-20 PSI.
AST TOOL manufactures an exceptionally engineered and well made fitting to accomplish this task. AST TOOL... If your repair shop is unable to show you this tool.for work requiring bleeding, then go elsewhere, or if doing it yourself, then go somewhere that does. ..or purchase one.
10-4 on the OE vs. aftermarket parts. I have zero doubt the OE ones are as good as or better than anything else. Just saying that sometimes an aftermarket solution is good enough and financially a better solution considering the state of the car. Not every car on this list is museum worthy.
On the bleeder option, I think different years have different procedures for bleeding the ABS. I know my '91 does not have any special ports on the ABS block, as later years do, and the procedure is to pressurize it and loosen the fittings to allow any air bubbles to come out. Luckily I've never got to a position where that is necessary.
I use a Motive pressure bleeder. It seems that can give the same "regulated" pressure as the special tool shown above, although from a different method. I don't typically pressure bleed at 15-20 psi. 10 psi usually does it just fine for me. But if ABS required 15-20, the pressure bleeder could just be pumped up to that. Same result, right?
I see that special tool is designed to be attached to an air line, which leads to the need for pressure regulation. But I'd be concerned that would also introduce very small amounts of oil and moisture to the brake system, if it is fed by standard air from a compressor.
And I always prefer to buy a general purpose tool vs. a special purpose one, since I'm the fleet manager for my family's stable of cars.
10-4 on the OE vs. aftermarket parts. I have zero doubt the OE ones are as good as or better than anything else. Just saying that sometimes an aftermarket solution is good enough and financially a better solution considering the state of the car. Not every car on this list is museum worthy.
On the bleeder option, I think different years have different procedures for bleeding the ABS. I know my '91 does not have any special ports on the ABS block, as later years do, and the procedure is to pressurize it and loosen the fittings to allow any air bubbles to come out. Luckily I've never got to a position where that is necessary.
I use a Motive pressure bleeder. It seems that can give the same "regulated" pressure as the special tool shown above, although from a different method. I don't typically pressure bleed at 15-20 psi. 10 psi usually does it just fine for me. But if ABS required 15-20, the pressure bleeder could just be pumped up to that. Same result, right?
I see that special tool is designed to be attached to an air line, which leads to the need for pressure regulation. But I'd be concerned that would also introduce very small amounts of oil and moisture to the brake system, if it is fed by standard air from a compressor.
And I always prefer to buy a general purpose tool vs. a special purpose one, since I'm the fleet manager for my family's stable of cars.
Not sure the procedure for bleeding 1991 ..I thought it was a dealer device that actuated the solenoids in the antilock brake unit..
When bleeding the antlock brake solenoid block on 1999, it is necessary to pressurize the master cylinder reservoir....hope whomever is doing it has a dry source or air
The other thing about these aftermarket purveyors of cheap reproductions...not going to encourage them to produce substandard parts by buying from them.
Left off my earlier list of aftermarket items that previous owner installed that I had to replace...Steering rack.
04-14-19, 09:31 PM
Brake master cylinder rebuild
