Master Cylinder Rebuild - DIY (1 Viewer)

[2001LC]

I would replace the wire and inspect the motor while you do and use the best one.

But your issue is not likely the motor based on your test, fact brakes work and what you mechanic said. Although it is possible the motor is intermittently working, which opening up motor you'll know.

If no other DTC (codes) found:

I could be in fuse box relay.

It could be your issues is in the black ABS units wires are attached to. The very first ABS system someone asked me to fix, seem to be very similar to what your experiencing and its wires were also bad, same year, about the same miles. He was quoted ~$5K to fix. We bought a used ABS unit from salvage yard, $100 worked great.

But these can be very hard to diagnose. May be worth your time and money to take to Dealership. Ask to have their master look at and meet with him. He too will like say replace the whole master assembly. But ask if he can narrow it down for you. They will not install just a part from a yard.

 

[QBLX470]

I would replace the wire and inspect the motor while you do and use the best one.

But your issue is not likely the motor based on your test, fact brakes work and what you mechanic said. Although it is possible the motor is intermittently working, which opening up motor you'll know.

If no other DTC (codes) found:

I could be in fuse box relay.

It could be your issues is in the black ABS units wires are attached to. The very first ABS system someone asked me to fix, seem to be very similar to what your experiencing and its wires were also bad, same year, about the same miles. He was quoted ~$5K to fix. We bought a used ABS unit from salvage yard, $100 worked great.

But these can be very hard to diagnose. May be worth your time and money to take to Dealership. Ask to have their master look at and meet with him. He too will like say replace the whole master assembly. But ask if he can narrow it down for you. They will not install just a part from a yard.

Thanks for replying. By used ABS unit you mean just the black plastic box or the complete assembly? I wish I could find one for 100$.

 

[2001LC]

Just black box on side of ABS. But be advise, safest is installing a new OEM complete assembly.

 

[RainCityCruiser]

Anybody knows the part number for the brake fluid reservoir grommets? Found some online but unsure if it's the correct one. Skidoo mentioned there's 2 different sizes.

 

[RainCityCruiser]

Anybody knows the part number for the brake fluid reservoir grommets? Found some online but unsure if it's the correct one. Skidoo mentioned there's 2 different sizes.

Found it. For those interested its..
4725516010 - 2x
3141735010 - 1x

 

[2001LC]

Found it. For those interested its..
4725516010 - 2x
3141735010 - 1x

Those are same I order. Haven't try yet!

 

[RainCityCruiser]

I just did an MC rebuild. Several months back I was experiencing a spongy brake pedal and long brake travels. I went to Toyota and they said MC looks ok and I just needed a brake flush since the brake fluid is dirty and then a brake bleed. This fix lasted around a little less than 2 months and the spongy brake pedal came back again. So, I ordered a rebuilt pump and the rebuild kit Skidoo mentioned in his first post. Replaced the parts and then cleaned the reservoir. This totally fixed my brake issue. I didnt really need to replace my pump but I was already pulling the MC out so decided to just replace it.

The LC brakes hard and feels like a different truck now. This rebuild saved me tons. Overall, I rate this rebuild a 2/5 difficulty.

The pump I bought: Link to Pump

This was my old piston. Not sure if this was really OEM.

Also, looks like Toyota never really did a brake flush. The brake fluid was really dark and green. It was really dirty when I flushed the system. My fault for completely trusting the dealership and not verifying the work done.

Brake fluid from reservoir. See all the black stuff?

Brake fluid after bleeding the system. (Dont mind the bottle cap)

 

[2001LC]

I just did an MC rebuild. Several months back I was experiencing a spongy brake pedal and long brake travels. I went to Toyota and they said MC looks ok and I just needed a brake flush since the brake fluid is dirty and then a brake bleed. This fix lasted around a little less than 2 months and the spongy brake pedal came back again. So, I ordered a rebuilt pump and the rebuild kit Skidoo mentioned in his first post. Replaced the parts and then cleaned the reservoir. This totally fixed my brake issue. I didnt really need to replace my pump but I was already pulling the MC out so decided to just replace it.

The LC brakes hard and feels like a different truck now. This rebuild saved me tons. Overall, I rate this rebuild a 2/5 difficulty.

The pump I bought: Link to Pump

This was my old piston. Not sure if this was really OEM.
View attachment 2130217

Also, looks like Toyota never really did a brake flush. The brake fluid was really dark and green. It was really dirty when I flushed the system. My fault for completely trusting the dealership and not verifying the work done.

Brake fluid from reservoir. See all the black stuff?
View attachment 2130218

Brake fluid after bleeding the system. (Dont mind the bottle cap)
View attachment 2130219

Do you have any pictures of brake control wire and inside of old motor you can share?

 

[RainCityCruiser]

Sorry for my ignorance but which one is the brake control wire? Ill post pics as soon as I can for the motor.

 

[2001LC]

S

Sorry for my ignorance but which one is the brake control wire? Ill post pics as soon as I can for the motor.

See posts # 324 & 326. Goes from bottom of black box (ABS unit) to motor on brake master assembly.

 

[RainCityCruiser]

Been busy doing other maintenance stuff on the LC but I was able to take some pics of the old motor (still functioning). Sorry no pics of the brake control wire.

 

[ClassyJalopy]

No - You will need to pull the clip off the clevis pin and then take the clevis pin out. Then loosen the check nut and then you should be able to adjust the length easily. I suggest being VERY CONSERVATIVE in adjusting the length because if you make it too long - it will drag the brakes.

Apparently I lied to you good folks

I decided to play with the brake pedal adjustment again today. You can definitely leave the clevis pin connected to the pedal. Just loosen the check nut and move the clevis by hand.
Looking down from the driver's position, I turned it clockwise 2 full turns and then tried to move the truck in neutral and found the brakes to be dragging. Kept turning counterclockwise, 1/8th turn at a time until brakes didn't drag anymore. Turned it back another 1/8th turn to give the brake pads some moving room and tightened up the 14 mm check nut.

Now there is almost no free play in the brake pedal ans the brake response is pleasantly immediate.

 

[Blake1]

well . . My mechanic did not line up correctly.. and broke the pin.. so internal part broke ... as this is not sold separately.. this basically sucks. As I am out a car for a while.

Anyone have this part they could share?

 

[2001LC]

well . . My mechanic did not line up correctly.. and broke the pin.. so internal part broke ... as this is not sold separately.. this basically sucks. As I am out a car for a while.

Anyone have this part they could share?

View attachment 2191861

I'm not sure what part you've pictured?

 

[Blake1]

This is the part that the (master cylinder rebuild for 50 bucks ) fits into (inside the master cylinder. LInes up as pictured

 

[Blake1]

 

[2001LC]

First time I've seen that pulled out.

Can you confirm; is that a rubber O-ring around it?

 

[jburris11]

My master assembly is also slightly wet with brake fluid on the front of the master and also under the plastic computer connection. I first noticed it happening after my truck had sat for awhile and the weather had gotten colder. My brakes seem to work fine and the pedal feel is also fine. No codes, abnormal noises or squeals. Do I need to remove the entire master assembly to replace the reservoir grommets and to also check the tightness of the 6 bolts underneath or can it be done on the truck? I figured the grommets were worth a try. I have a 2000 model LC with 153K.

 

[2001LC]

Most common reason for wets net is over filling. Make sure to read topping procedure that's embossed on the reservoir.

 

[jburris11]

Most common reason for wets net is over filling. Make sure to read topping procedure that's embossed on the reservoir.

Thanks...I have followed the procedure and the level is spot on. Do I need to remove the entire assembly to remove the reservoir or is it possible to do it with the master in the truck?