Otto Mechanic

I'm in the midst of bleeding my brake and clutch hydraulics. That's the baseline. I've removed all of the hydraulic lines to the brakes and replaced them with braided stainless (Goodridge if you must know). I removed the clutch slave and replaced it. I've made no changes to the master cylinder.

After bleeding the rear brakes, then bleeding the slave, then bleeding the front brakes, I had a working system.The brakes were firm and the clutch was working within spec.

I had filled the system with ATE yellow to begin, with the idea I'd use ATE Racing Blue to finish. That way I'd know (visually) I'd completely bled the system by watching for a color change in the fluid. I've used this technique for decades to assure I've done a complete system bleed by alternating fluid color.

After completely bleeding the hydraulics using some older ATE Blue, I decided to add 1 liter of new ATE Blue I had on the shelf and continue the bleed. I finished bleeding both rear calipers, then bled the slave cylinder again. This is where I began to have trouble.

The slave just blew air. I was using a Motive Power Bleeder and the entire system was pressurized, but there was no fluid in the Motive, just air. The reservoir was full to the top with ATE Blue, but when I opened the clutch slave bleed screw it Just blew air, and lots of it. Air. Pump up Motive. More air. Pump up again. More air. Mind you, all four calipers were clean of bubbles and showing blue fluid.

I thought it might be the orientation of the car, which was jacked up on the front using a sliding rack jack. i put the wheels back on the front and dropped it back down to level. Filled the brake reservoir again to the top of the cap, re-pressurized the hydraulic system with the Motive, and tried bleeding the slave cylinder again. No joy, it just kept spitting air.

The clutch pedal itself stopped working.

I think I'm just short on fluid. I have 2 liters of ATE yellow that should be here tomorrow and plan to run all the Blue out of the system until I see gold at each caliper and also get the slave working again. If there's some reason to think there's another problem, for instance a slave or master cylinder failure, I'd like to hear opinions?

The factory service manuals don't mention total fluid capacity for the hydraulics, only that the calipers require 1 liter. I haven't been able to find specs for the master cylinder, slave and calipers. If anyone knows the full specs and can tell me how much fluid I need on hand to completely flush the calipers and the slave, I'm all ears?

Thanks,

PaulD_944S2

The brake fluid reservoir is a bit tricky.
There is a small divider that separates the clutch from the brakes. You have to have the reservoir full ALL the time to get fluid to the clutch master and slave cylinders.

Otto Mechanic

Thanks for confirming that Paul, it's pretty much exactly what I guessed.

So the reservoir needs to be level during the bleed and it needs to have fluid available above the "max" line while bleeding the clutch (in your experience). The manual doesn't mention it, but it's good to have a practical confirmation.

Best Regards,

odonnell

Literally happened to me last night, including jacking up the car at the rear. Can confirm it's a fluid level thing.

Question... when you got the line reasonably bled, was there still an inch or two of light travel before your pedal started to feel pretty firm? I'm trying to figure out if this is normal or if my clutch master is on the way out. There's not a lot of adjustment on the clevis so I don't think it's a free play issue. I can't remember what it felt like the last time I bled it 2 years ago.

Van

See that little blue hose coming off the reservoir going to the brake master? The brake fluid level has to constantly be above that.

GPA951s

I have heard that you can Drill a hole Through the port that that hose comes off, (Allowing fluid to flow more free into the chamber for the clutch) But the EASY way to do it is with a Piece of Vacuum hose attached to a Syringe, and Purge the System from THE BOTTOM UP. 9 times out of 10 Im alone in the garage so I came up with this,
Empty top Res, Fill the Syringe (Its a BIG Syringe) I Start Squeezing the Syringe As I am attaching to the bleeder and at the same time open the bleeder and push the fluid from the bottom up, about 2x and it takes about 5 to 10 min and done. I Like this method because air bubbles need to go up, its such a pain making them go down. I used to know a Veterinarian who took care of horses, Hence the BIG Syringe..

Tiger03447

How big is the syringe? 200cc's or larger? Some of the irrigation syringes are that large, and could be even bigger, now that I think about one for irrigating out ear canals. But that was many, many years ago..and it was metal. probably held at least 1/2 pint..and did not have a Luer lock end on it. Might find one in a war surplus place..since it was an army medical item..

marc abrams

Why don't you try it with power bleeder filled with brake fluid? That's how it's suppose to work. Be sure to clean the power bleeder with denatured alcohol after use.

Otto Mechanic

Well... because I'm out of fluid?

Amazon will be delivering two more liters sometime today. I was pretty sure that was the problem, but it was still a mystery. I'd run up a ladder (car was up on a lift), check the fluid reservoir was full to the top, back down the ladder, open the bleed screw and get a sputter of bubbly fluid then air.

Repeat. 3 or 4 times. It just made no sense.

My guess is once I ran out of fluid in that line, I never had enough fluid left in the reservoir to do more than get it a little wet before the level dropped below the intake line, so I was "in a loop". I needed fluid in the Motive to make it work.

Which makes me wonder how people solve this problem without a Motive. I suppose two people could do it, or there's the aforementioned syringe method GPA describes (which I'm not certain I understand yet).

Otto Mechanic

I only had it working for a few minutes, but my recollection is it was firm from the start. I'd hate to base your diagnosis on that though since:

a) I wasn't really paying close attention and was pleasantly surprised when the clutch peddle didn't just go to the floor and stay there.

b) I haven't driven the car in two years and can't remember what "normal" is either.

I'll be bleeding it again this afternoon or tomorrow depending on when UPS shows up with more fluid so I'll report back when I get it working again. This time I'll pay closer attention.

Thanks for the confirmation!

Otto Mechanic

As a sorry side note, that was my last can of ATE Blue. I'm thinking of driving to Mexico and buying a case of it now that it's illegal in the US.

First they came for the Communists, and I did not speak out...
then they came for my brake fluid...

Would that make my car an "outlaw"?

GPA951s

I would think any VET would have it Esp if they deal in horses... Mine has a Tip on it, no needle where a piece of hose can go, and worse case you can suck the fluid from the top reservoir and push it right back in through the bottom, hardly have to use any fluid... Or Just Google it, Even if you get it bled without it..VERY handy and effective... I was at the track and spent hours trying to manually bleed one I re-built on the spot... My Wife brought me my syringe from home and I on the track in 10 min... I keep mine in my "Specialty tools" Drawer.. And for good measure.. Replace the hose that goes from the Res to the Master...

Otto Mechanic

OK, I got this.

I think you could do the same thing with the plastic collection bottle I use at the bleed valve, it has a correctly sized soft plastic hose that fits over the bleeder already. If I filled it with fluid, turned it upside down, opened the bleeder and squeezed the bottle it should do the same thing as your syringe, forcing fluid back up the line to the reservoir.

I might give that a try.

StoogeMoe

You don't need a vacuum system. The Motive works fine.

You don't need to put fluid into the Motive either. I never do, because I hate cleaning it afterwards. Like the others said, make sure you have enough fluid in the reservoir to cover the clutch master hose. Jack up the rear of the car to make this easier.

You're using Blue? Didn't they stop making that? If so, your Blue is probably old too. I would get that out of there.

Otto Mechanic

It's illegal in the US now, I don't think they stopped making it.

The can was only a year old and hadn't been opened, I doubt it would be a problem, but like I say, I'm planning to do the final system flush with amber.

The purpose of using the blue is to get all the air out of the lines, calipers and cylinders. After that's done, a final flush with amber is used, assuring the entire system has been flushed by watching the color change at each bleed port.