sleeper408

iTrader: (6)

Hello everyone,

I recently had a shop swap out my stock brake lines for Goodridge SS brake lines on all four corners and I'm experiencing a brake fluid leak which I believe is coming somewhere from the master brake cylinder. There are no leaks coming from the brake lines themselves.

Just some quick info on my car: It's a '98 GS400 with 136,000 miles and there was not a single drop of brake fluid leaking anywhere before upgrading the brake lines. I also have TT Supra brakes in the front.

6/18 - Goodridge SS brake lines were installed. Drove home with no issues and brakes felt great.

6/19 - I first noticed the leak when I was parked on my driveway and checked underneath the car in the morning. There was brake fluid all over my driver's-side lower ball joint and a small puddle directly below. I then moved my car to the street where it is more leveled. I popped my hood and checked the brake fluid level - it appeared that it was filled right up to the max fill line and maybe even a smidge above that line, so I just dismissed the leak as overflow from the reservoir.

That morning, I brought the car back to the shop for a second opinion and the mechanic put the car on a lift and did an inspection. He could also clearly see a lot of brake fluid on and around the driver's-side lower ball joint. Inspection while the car was on the lift didn't produce any answers. He lowered the car back down and took a look under the hood. He said he couldn't find the source of the leak as he even used a small mirror to check under and around the master brake cylinder. My suspicion is that the leak is somewhere in the back of the master brake cylinder very close to the firewall.

He said, the brake fluid was probably slightly overfilled and that the leak is just overflow from the reservoir. He said this happens on occasion and is nothing to worry about as the fluid level will eventually fall below the max line. I agreed and left for work.

Well, the leak has been occurring on and off over the past few days. The thing is, the leak only occurs when I park on a sloped surface (E.g. my driveway). If I park on the street (which is leveled for the most part) there is no fluid that drips to the ground when I check underneath a while later.

6/22 - I checked my brake fluid level in the evening and it was about 1/2" - 3/4" below the max fill line. I figured that it isn't overfilled anymore and it shouldn't leak, so I moved my car to the driveway confident I wouldn't see any more more brake fluid on the ground from there on out.

6/23 - I came out this morning and there was a cookie-sized puddle of brake fluid right below where the lower ball joint is.

I took my car back to the shop and left it with them hoping to get it back today. They didn't have time to work on the car so I left it over the weekend until they can look into it again on Monday morning.

I apologize for the long read, but I just wanted to describe the issue in detail in case someone else has dealt with the exact same issue and might be able to provide me with an answer.

- Has anyone experienced this problem right after upgrading their brake lines to SS brake lines?
- Is it possible they used the wrong type of brake fluid for higher pressure SS brake lines and the high pressure is forcing the fluid out somewhere?
- Is my master brake cylinder on its way out and it just can't handle higher pressure that the SS brake lines produce?

Any advice would be greatly appreciated! Thanks in advance!

- Theo

tmf2004

iTrader: (15)

i was going to say the same thing about the brake reservoir being over filled but it could possibly be a leak in the line somewhere...

SorrGwa

iTrader: (1)

did you change the copper crush washers at the banjo end of the brake lines?

the new lines should have came with them, 2 on each banjo end so it goes brake line bolt, copper crush washer, banjo brake line fitting, crush washer, brake caliper.

do not reuse old ones, but if must, make sure they are clean.

sleeper408

iTrader: (6)

I'm not entirely sure. I bought the set BNIB from a forum member and I don't exactly remember if those were all in there. Could this be a possible cause of the leak coming from the master brake cylinder?

sleeper408

iTrader: (6)

I'm hoping it's only a leak in a line or hose coming from the master brake cylinder and not the unit itself.

SorrGwa

iTrader: (1)

its possible. but you said its by the ball joint, so the caliper would be the closest.

i usually would start from the point of where any parts was removed. jack the car up, turn the wheel to one side, and take a look at where the caliper meets the line, look to see if its wet with brake fluid there.

FrankT

This has happened to me...
Brake fluid was over filled and was soaked up by the firewall insulation.
It's just taking a few days to flow through and drain out. Clean the area with brake cleaner...

sleeper408

iTrader: (6)

Thanks for responding, Frank. I haven't thought of that scenario and I think you may be correct. The car has been at the shop for a few days now. The mechanic cleaned the undercarriage and wiped down the master brake cylinder and that area. He said he drove it a bit and also parked on flat and sloped surfaces with no visible brake fluid leaking from the cap, hoses or at the lower ball joint where fluid was originally found.

djcobra

I had a similar problem when I replaced my pads and rotors. The fluid level looked fine, near the max line but over night it just leaked out of the brake fluid cap and it was all over the master cylinder (and floor). So I syphoned the extra fluid out just so it read below the MAX level, cleaned around the master cylinder. As FrankT mentioned the firewall insulation soaks up alot of the brake fluid and it will drip slowly, probably freaking you out that there is a leak somewhere (lol). Anyways, its all good now.