Brake Fluid in Brake Booster - Master Cylinder Issue?

[Wwevo]

Hey everyone, I was working on my 2002 TJ Wrangler and noticed something odd. While removing the master cylinder for a deep cleaning (I was in the process of replacing all the brake lines since they were really rusted), I found brake fluid inside the brake booster. The brakes were working fine before I started this project, but I’m concerned now.

Does this mean my master cylinder is bad? And should I be worried about the brake booster as well?

Any advice would be greatly appreciated. Thanks!

 

[Obi-Wan]

Hi there, welcome to the forum.

I summon the overwhelming knowledge of @mrblaine for any brake / brake booster related issues. He is the go-to for his extensive knowledge in this area.

 

[mrblaine]

Hey everyone, I was working on my 2002 TJ Wrangler and noticed something odd. While removing the master cylinder for a deep cleaning (I was in the process of replacing all the brake lines since they were really rusted), I found brake fluid inside the brake booster. The brakes were working fine before I started this project, but I’m concerned now.

Does this mean my master cylinder is bad? And should I be worried about the brake booster as well?

Any advice would be greatly appreciated. Thanks!

Yes to both. Oddly, the diaphragms in brake boosters are not compatible with brake fluid so they will die before long.

 

[macleanflood]

If the brake lines are that bad, how about the fuel line and frame?

-Mac

 

[Wwevo]

Hi there, welcome to the forum.

I summon the overwhelming knowledge of @mrblaine for any brake / brake booster related issues. He is the go-to for his extensive knowledge in this area.

Thank you Obi-Wan

Yes to both. Oddly, the diaphragms in brake boosters are not compatible with brake fluid so they will die before long.

Okay thank you, I ordered the Raybestos master cylinder BPIMC390378 (https://www.amazon.com/dp/B000C73MQA?tag=wranglerorg-20) and SKP SKBB057 brake booster from rock auto. It’s the best I can find that’s available since mopar has discontinued their version.

 

[Wwevo]

If the brake lines are that bad, how about the fuel line and frame?

-Mac

The fuel lines are actually in good shape with no rust. As for the frame, I’ve already taken it down to bare metal and applied an epoxy primer to protect it. The brake lines, however, were a different story. When I was disconnecting the front brake lines from the frame, one of them crumbled due to rust, which is why I decided to replace all the lines.

 

[nitrofalcon]

The fuel lines are actually in good shape with no rust. As for the frame, I’ve already taken it down to bare metal and applied an epoxy primer to protect it. The brake lines, however, were a different story. When I was disconnecting the front brake lines from the frame, one of them crumbled due to rust, which is why I decided to replace all the lines.

View attachment 559501View attachment 559502View attachment 559503View attachment 559504

Be careful lifting the car on Is cinder blocks. I personally wouldn't get under a car on them.

 

[cliffish]

Be careful lifting the car on Is cinder blocks. I personally wouldn't get under a car on them.

Looks to have stands at all 4 corners, the blocks are probably for the skid plate or transfer case.

 

[ColoJeep]

Be careful lifting the car on Is cinder blocks. I personally wouldn't get under a car on them.

Also rotate the blocks 90 degrees and position them the way the blocks would be built into a wall , then put a board on top of them.

( This is the right way to do the wrong thing ! ) .

 

[lBasket]

View attachment 559502

Are these extra body mounts

 

[Wwevo]

Be careful lifting the car on Is cinder blocks. I personally wouldn't get under a car on them.

I had Jack stands on the axle 4 corner and the cinder block holding the transmission (transfer case was removed) so I can have access all around the frame as I was cleaning and painting it.

 

[Wwevo]

Also rotate the blocks 90 degrees and position them the way the blocks would be built into a wall , then put a board on top of them.

( This is the right way to do the wrong thing ! ) .

You got it lol

 

[Wwevo]

Are these extra body mounts

The earth are my mounts

 

[James9100]

Okay thank you, I ordered the Raybestos master cylinder BPIMC390378 (https://www.amazon.com/dp/B000C73MQA?tag=wranglerorg-20) and SKP SKBB057 brake booster from rock auto. It’s the best I can find that’s available since mopar has discontinued their version.

@Wwevo How’s the SKP booster holding up for you so far?