Possible brake system leak

[714dre]

I think I may have a leak in my fuel system.

I just purchased a Motive bleeder, and did the initial 'pump it to about 10PSI' to ensure no leaks before doing the full flush.

Well, it does not hold the pressure... within a few minutes it will drop a few pounds. It is slow, but is definitely leaking.

I disconnected everything, reconnected and tightened as hard as I dare tighten it, but get the same result.

My question for the group is what is my best bet on diagnosing this?

I don't see any leaks on the ground below the car...

The brakes feel fine on the car.

At first I thought maybe the power bleeder connection to the reservoir was it, but I tightened it so much I am pretty sure I can rule that out.

So guys, any tricks to tracking this down? Thanks

[logray]

Did you put the rubber washer thing inside the cap that screws onto the reservior?

[JFP in PA]

The Motive unit is leaking, not your brakes. You need to go over the Motive unit carefully and find the leak (cap, seal, connections, etc.). If you had a hydrualic system leak, your brakes would not be "fine", they would not work properly, if at all..............

This is exactly why I always caution first time users of the Motive system, which is an excellent tool, to pressurize the system empty first to about 12-15 PSIG and make sure it is tight before filling the system with brake fluid.

[714dre]

Thanks guys.

I did get the washer on the cap and I'm confident that connection is good.

I'm thinking its leaking at the other end since thankfully it sounds like my system doesn't have a leak.

so with the bleeder leaking slowly, would it even matter if I did the fluid by only filling the reservoir, not the motive?

I think I've read about that method on here, and at least I could do the flush this weekend.

[JFP in PA]

I would connect the Motive unit to the car empty, pump it up to about 10-12 PSIG, and then start squirting or use a small brush to coat each and every one of the connections on the unit with a mixture of dishwashing soap and water; one or more of the connections should start blowing bubbles, and is become the focus to tighten until the bubbles stop. Once the leaks are corrected, the unit will be permanently repaired.

Yes, you can go the "two man route" and keep opening, refilling and capping the brake reservoir, but it is time consuming as Hell compared to using the Motive unit, and dramatically increases the possibility of spilling brake fluid on a painted surface. I'd fix the Motive unit and be done with it, we have used Motive units in the shop for years; they work quickly and efficiently, and are by far the best tool for the job.