Brake fluid leak from line or master cylinder (2 Viewers)

[Mantyrge]

Hello, I am a new 100 series owner and as I've been driving it lately I started to notice some brake fluid leak on the ground under the driver side. After reading a lot of the posts here none of them seemed to match to what I think may be happening, but I just can't figure it out. After cleaning everything up and laying some towels down to see where the leak is coming from I noticed a drop of brake fluid handing from the line connecting to the master cylinder. In the attached pics is the red circled one. From there I noticed another drop on the red line below it thinking its from the dripping down. I looked all over and I couldn't really see any other place it was leaking.

I tried to tighten the line a little to see but I am still getting a leak. My brakes work fine and the pedal feels firm and there is pressure in the system. Is there anything I can look at or is this something can be repaired without having to get a whole new master cylinder? I'm not the most mechanically inclined but am trying to learn. Thanks for any adivce.

 

[2001LC]

Red hard line, is very high pressure line. If it was to have leaked, you have a pressure drop. Booster motor be running excessively. You may even get brake alarm.

I see oil on brake control wire boot. Not good! Since brake fluid gets in the boot and on wires/contacts/screws, attracting moisture.

Whereas you can have leaks in a few places on master. The most common so-called leak I see, is actually from over filling reservoir. It then comes out the reservoir cap. Read what is embossed on the reservoir, and set level as it instructs.

Set level properly, clean. Then see if leak reappears. If it does:

A second leak, may be grommets (3) at bottom of reservoir. This is not common, unless reservoir has been removed at some point.

A third leak, is from between brake master and ABS (black box of side of master). Replace the whole master, is the cure!

A fourth is at base of accumulator (sliver/gold cylinder on side of master) has an O-ring. Again not common unless it's been removed. You can see if loose, just by trying to tighten by hand (grab the whole cylinder at top, and turn CW).

Hard-line leaks, we do not see. Unless someone has had them off or rusted through. Do not over-tighten their flare nut, which may damage the flare.

Brakes ...... Overdue write-up.

First and foremost: Brakes should only be worked by those, with high level of mechanical abilities and experienced with brake systems. With the age of all 100 series today, in our aging fleet. Any issue, with brake master assembly. IMHO, best and safest course of action. Have the whole brake...

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[NE Snowman]

My master was leaking out of the black plastic on the drivers side, it would work over under the master and drop on the hard lines. A new master and booster fixed my problem.

2001LC nailed mine, leak between master and ABS.

 

[Mantyrge]

My master was leaking out of the black plastic on the drivers side, it would work over under the master and drop on the hard lines. A new master and booster fixed my problem.

2001LC nailed mine, leak between master and ABS.

View attachment 3485317

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Thank you both for the response. I have a feeling its the same thing NE Snowman. The brake booster was recently replaced at the dealer but the master was not. May need to get a new master then.

 

[kevgentile]

As previously mentioned, Clean and dry very well and apply pressure. Come up with a makeshift depressor or have someone hold steady pressure while you look for the leak.

Mines leaking from the resi to mc seals

 

[uHu]

99% it is either overfilling (because you didn't RTFM) or the grommets under the reservoir.
But, when I hear that professionals (someone who does not work for the love of your car) have been involved, I get suspicious.

 

[Mantyrge]

99% it is either overfilling (because you didn't RTFM) or the grommets under the reservoir.
But, when I hear that professionals (someone who does not work for the love of your car) have been involved, I get suspicious.

Thanks, I have a few things to check and hopefully its one of those two things. I'm reading through stuff and researching trying to learn more.

 

[kevgentile]

Thanks, I have a few things to check and hopefully its one of those two things. I'm reading through stuff and researching trying to learn more.

Just don't let that brake fluid sit too long on the fender well and frame. The lx I just got had a leak and since it had a crank/no start since March it just sat while brake fluid leaked on to the surfaces below. Bubbled up the fender well paint and lifted the paint on the fame rail. Fortunately, it was garage stored and suffered no corrosion. Just need to clean and refinish once I address the no start

 

[flintknapper]

My money would be on M/C grommets.

 

[Mantyrge]

My money would be on M/C grommets.

View attachment 3486728View attachment 3486732

Is there a good tutorial on how to remove them?

 

[Mantyrge]

I went out there and cleaned off as much as I could and dried it off. I laid down some shop towels under the MC and also along the bottom of the reservoir to see if I can identify where its coming from.

 

[flintknapper]

Is there a good tutorial on how to remove them?

Nothing to it really. Just pluck the old one's off and put the new ones on. (One is smaller than the other two). No more
leak.

Because I know someone is going to ask:

 

[Mantyrge]

Nothing to it really. Just pluck the old one's off and put the new ones on. (One is smaller than the other two). No more
leak.

View attachment 3486943

Because I know someone is going to ask:

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View attachment 3486947

Awesome, thank you. It seems the reservoir isn't help on by much but a few screws.

 

[40to100]

Hello- recently went through this same issue- leak located in same spot on red line. Prev owner had replaced accumulator but not MC ( thought I was safe!) Was leaking from MC and got to point where accumulator was beginning to run more often. Replaced with reman from Andy Le.

 

[Mantyrge]

Update: So I kept cleaning everywhere I thought the leak was originating from but I just couldn't find where on the MC it coming from. I did notice after cleaning that fluid spot on the ground was a little offset from the frame, still below the driver side though. So cleaning the lines next to the frame and just the right lighting I saw this on one of the lines.

I am thinking I may have some small cracks here that are causing brake fluid to leak a bit.

 

[2001LC]

Update: So I kept cleaning everywhere I thought the leak was originating from but I just couldn't find where on the MC it coming from. I did notice after cleaning that fluid spot on the ground was a little offset from the frame, still below the driver side though. So cleaning the lines next to the frame and just the right lighting I saw this on one of the lines.

I am thinking I may have some small cracks here that are causing brake fluid to leak a bit.

View attachment 3488986

Not uncommon for the protective plastic coating, to show cracks. Those are usually not a leak point.

You've a lot of fluid on all those lines. Clean again with degreaser and watch as someone presses brake pedal hard, with key on. If that's a leak, it will then show.

Note: After cleaning, inspected to make sure perfectly clean, before activating brakes.

 

[Mantyrge]

Not uncommon for the protective plastic coating, to show cracks. Those are usually not a leak point.

You've a lot of fluid on all those lines. Clean again with degreaser and watch as someone presses brake pedal hard, with key on. If that's a leak, it will then show.

Note: After cleaning, inspected to make sure perfectly clean, before activating brakes.

Thanks for the info. I cleaned and found that the leak is still coming from the MC area.

I responded in another thread with this question but it was an old one, a few years, that I'm not sure anyone will see. I'm hoping its the grommets because that's a bit cheaper so if I were to replace them do I need to take the entire MC out to remove the reservoir or can I remove it while on the vehicle?

 

[2001LC]

Thanks for the info. I cleaned and found that the leak is still coming from the MC area.

I responded in another thread with this question but it was an old one, a few years, that I'm not sure anyone will see. I'm hoping its the grommets because that's a bit cheaper so if I were to replace them do I need to take the entire MC out to remove the reservoir or can I remove it while on the vehicle?

You can pull just the reservoir, without removing master assy.

But first, I'd try to isolate area leak from.

Assuming the fluid level has been set correctly. I'd get pictures of the space between reservoir and master assemble. See if any area on top master is wet.

 

[Mantyrge]

You can pull just the reservoir, without removing master assy.

But first, I'd try to isolate area leak from.

Assuming the fluid level has been set correctly. I'd get pictures of the space between reservoir and master assemble. See if any area on top master is wet.

Thank you for the replies, its been really helpful. I guess I didn't pay attention previously but from what NE Snowman showed I see the same thing. It appears to be wet/moisture on the lower portion of the black box on the side of the master. The booster was replaced by Toyota a year ago but not the MC unfortunately.

 

[2001LC]

Thank you for the replies, its been really helpful. I guess I didn't pay attention previously but from what NE Snowman showed I see the same thing. It appears to be wet/moisture on the lower portion of the black box on the side of the master. The booster was replaced by Toyota a year ago but not the MC unfortunately.

If not wet on top near grommet. But wet at bottom from between master, silver spacer and black box. You'll need a new brake master with booster assy (the whole master assy). I know you have a newish booster. But best price point is the whole assy. You can sell your old booster assy.

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