EZ BLEED problem?

[70S Targa Guy]

Today I put on new brake pads (updated the 911S calipers and rotors to 84 Carrera brakes years ago) on my 70 911S. I usually have my wife sit in the car and pump the brake pedal while I go to each corner and loosen the bleeder to bleed the brakes the old fashioned way. I have heard some talk on this forum regarding the EZ BLEED system so I decided to give it a try.

The directions say to use a spare tire inflated to 20 PSI max. Since this was my first time I figured I would be cautious and have the spare tire filled to 17 PSI. I put the proper EZ BLEED kit cap on my brake fluid resevoir, filled up the EZ BLEED canister with about 16 ounces of Dot 4 brake fluid, securely hand tightened all the lids and connected the EZ BLEED air valve to my spare tire. Immediately thereafter and before I went to the right rear bleeder nipple, I noticed immediately the level of the brake fluid in the EZ BLEED canister was lessening and being drawn into the car's brake fluid resovoir. I was thinking that only an ounce or two at most of the brake fluid should be transferred at this time as no bleeder nipple had been opened yet. I kept watching the level of the new fluid in the EZ BLEED canister getting lower and lower. After about a total of 10-15 seconds I heard the sound of brake fluid dripping on the ground. The fluid was dripping from the middle front of the car around the vicinity of the middle part of the steering rack. I suspect that the pressure created by the EZ BLEED system and spare tire air pressure forced brake fluid out a hose connection or some seal in that vicinity. I immediately disconnected the air valve from the spare tire and checked my brake pedal. It was fine. It appears no air got into the system (I think anyway) but fluid definately got out of the closed? looped system. I didn't have the opportunity to get underneath the front part of my car and see the source of the leak. Does anybody have any ideas as to why and where this leak occurred. (Clutch Slave Cylinder??) I never used this EZ BLEED before so I don't know if you should go to the bleeder nipple and open it IMMEDIATELY after you connect the valve to the spare tire or what. Any help would be appreciated.

[dan79brooklyn]

Do you have to pinch off the overflow hose that connects to the reservoir?

I bled the brakes with my Dad over the thanksgiving weekend. We did the pump and open close routine it worked well except for some slightly buggered bleeder nuts that will need to be replaced...

Where did you buy the EZ bleed kit?

[70S Targa Guy]

There's an overflow hose?

Wow, I never knew there was an overflow hose to the brake fluid resovoir. Where is the end of this hose that needs to be crimped located? If there is one I didn't seal it up. That makes sense because I went through about 8 ounces of brake fluid in about 15 seconds.

I bought my EZ Bleed locally (PA) for about $42. I will dig up this guy's website and post it. He does mostly mail order.

[70S Targa Guy]

Maybe I'm blind or it was well hidden or possibly removed, but I did not see any overflow tube coming off the brake fluid resovoir. Anybody have any knowledge of an over flow pipe for the master cylinder that could be the culprit during my bleeding process?

Has anybody had any experience with the MC seals leaking brake fluid when applying 17 PSI with a pressure bleeder?

As promised, here's the link for the EZ Bleed system: http://www.rdent.com/pages/tools.html

[Jim Sims]

"well hidden or possibly removed"

"Molded in" plastic hose barb (for overflow hose) should be on the REAR, top side of the resevoir; they can be broken off leaving a small hole which is nearly impossible to seal against pressure.

"Has anybody had any experience with the MC seals leaking brake fluid when applying 17 PSI with a pressure bleeder?"

Yes; if original, the 35 plus years old rubber grommets sealing/ securing the supply lines to the top of the MC will leak and or jack themselves out under that level of pressure. If this has happened you will likely find brake fluid on the top surface of the splash pan and leaking downward. New rubber grommets are available.

[1980 911 sc]

i did same thing with my Motive power bleeder, was the overflow hose not being sealed.

[Jim Sims]

Correction: overflow hose barb will be found on REAR, top side of reservoir.

[70S Targa Guy]

Thanks for your replies. You guys were right. The brake fluid was coming from the broken off barb that used to house the overflow hose. As you can imagine it created quite a mess that required a thorough cleaning.

Note to self: Next time I use pressure bleeder to bleed brakes on my 911 remember to lift up trunk carpeting away from brake fill resevoir.

[joe payne]

I put Speed Bleeder's on all calipers and and made life easy.
Not sure if they make them for your calipers. Check our host.