New MC assembly bleeding issues (1 Viewer)

[squidmotion]

Long story short, and let me preface this by saying Andy Le is very easy to work with, and I have absolutely no complaints with him or his service.. I’m just unlucky it seems.

However, after two rebuilt MC assemblies from Andy, the first one started leaking, second lasted one day, then I had a total brake failure. I can’t abide this, as my girls drive this machine sometimes.

So I ordered a brand new assembly from Toyota.

I haven’t had any bleeding issues with the rebuilt units, but after installation of the brand new Toyota unit I’m going through the usual bleed procedure with no luck at all. I feel like all I’m doing at this point is pushing new fluid through the system, but the pedal remains soft.

Cleared the ABS/Brake code, but the BRAKE light is still on, probably from the low fluid level. I’ve done the 40 pumps, then the bleed process for the rear. No luck. Then bled the front, seemed to get better, then pedal goes to the floor again. I’m not leaking anything. Brakes are in good shape, lines are in good shape. no rust anywhere, bleed screws are fine.

I’ve done this three times now, and gone through 4-6 bottles of fluid, still no luck, pedal goes right to the floor. I’ve done the rear, then the front, and the front again, and then the rear again. I’ve never let the MC run dry. Everything worked fine after bleeding the last two rebuilt MC units.

I clearly have air in the system still, or is it something else? The motor runs as normal, no more than 40 seconds.

I’ve searched and researched all the Mud forum posts..

What the hell am I doing wrong?

 

[x8o8drifter]

So just for clarification. When you say you've "gone" through 4-6 bottles.
Does that mean you have put 4-6 bottles in it and none is coming out? (less the tiny amount from cracking the bleed screws)
Air in the ABS block itself maybe? Should be something in TS to help bleeding that.
Caliper line and ABS flush using Techstream

 

[squidmotion]

So just for clarification. When you say you've "gone" through 4-6 bottles.
Does that mean you have put 4-6 bottles in it and none is coming out? (less the tiny amount from cracking the bleed screws)
Air in the ABS block itself maybe? Should be something in TS to help bleeding that.
Caliper line and ABS flush using Techstream

Thanks for the reply and the link x8.

I've bled out through the bleeders 4-6 bottles. I've removed air from the front, and rears, but still have a soft pedal. I'm not using TechStream, but I am using the MC motor running to bleed out the rears, as I did the previous times.

 

[nissanh]

Link to my install: LandCruiser 100 Brake Master Cylinder Installation - The Easy Way! - https://forum.ih8mud.com/threads/landcruiser-100-brake-master-cylinder-installation-the-easy-way.1293213/

On the first post I followed the sticky note instructions to get the master ready (It was from a youtube video posted by a toyota mechanic in Moldova). It worked for me 100%

Watch the video posted in the first post
Note 19 tells about bleeding the rear brakes.
front showed no sign of bleeding.. just few drops. The ideo tells the front will bleed on it's own and it worked for me. I drove on a dirt road and (WITH no one behind) I locked the brakes o activate the ABS. That's all I did for front and brakes are solid for past 3 years!

 

[TahoeZ]

Procedure is bleeding fronts first, then rear, then tech stream bleed. A lot of air came out of both that I replaced during the tech stream bleed.

If you still have a soft pedal after that you either have a leak or a faulty MC.

 

[squidmotion]

I bled the front, then the rear…. then the rear and the front again…. another hour and another 3 pints of fluid.. i’m up to almost a gallon now.. and no luck. Starting to think my luck is so bad that I have a bad one from the factory. I bled it this time with the key turned off, then again using the motor to push fluid for a few minutes.. no more air. still, the pedal goes to the floor. Went over the entire truck to check for leaks, or bad hoses, etc.. nothing. NissanH, i followed your instructions, just like I did the last two times to success. No love this time.


also no longer getting the slack pedal to evacuate the system after the 40 pumps.

getting pissed off to the highest of pisstivity, as my wife likes to say.. hahhaahah.

Any other suggestions, friends?

 

[nissanh]

When I removed mine, I simply disconnected the lines and wires (battery removed).

On my sticky note: line-6: Foot off... Ignition on wait 1-2 minutes: I heard the ABS pump kicked in and system got pressurized. Did you notice it?

Line-9 Ignition off... open lines (foot off). I noticed no fluid leaking out at the lines at fittings to the master

Line 10: Ignition on. Still no fluid spraying out from the lines to master joint

Line-11 (last line) hold brakes... A lot of fluid started gushing out from all 4 lines. While this is happening, I tighten all 4 lines.

Did you experience these symptoms?

Also, are you sure you have all wires connected properly? any bent pins in any of the connector?

Does the ABS motor run? do you hear it?

 

[leveeguy]

I understand you ran 4-6 bottles through bleeders but if two, three maybe good bursts of air didn't bleed out there could be air trapped.
I like to bleed using clear tubing which helps with seeing the amount of air removed at each corner. Seems the rear passenger side usually has most air in my experience
You may try to park with on slight angle if vehicle was perfectly flat on previous attempts.

One of my buddy's installed a caliper upside down (not on a cruiser) and on the opposite side on one occasion, not even sure how that was accomplished but what it caused was the bleeder to be on the bottom and during bleeding the pedal would stay soft. Air was trapped at top of caliper was the reason due to bleeder incorrectly positioned at the bottom of caliper. Im not saying you have this condition but just a reference for the area air can get trapped in system.

Edit: Didnt notice it mentioned i dont think, but you're using toyota brake fluid or DEX III as compatible with your 99 LC, id assume?

 

[daohaus]

Did you watch Timmy the toolman’s video of changing out the MC on the 100 he’s pretty detailed in the video