850 Hydraulic clutch Issue

[Chuck W]

My brake master cylinder reservoir only has 1 outlet port on it, and it is on the left side, back towards the brake booster. That should be the one you use for the clutch. I don't know why you have 3 ports on yours and what other systems might be using brake fluid.

You can barely see the connection on my '97 between the throttle cable and the brake fluid reservoir.


The reservoir is just to hold fluid. Nothing more. It shouldn't matter which port your feed to your clutch master is from.

[manovlov]

Salut Chuck W,

This is just a track I was looking at. I think these 2 "Pro version " of master cylinders sold by the seller were not done like they should have been.

I've ordered ATE S.C. , new fluid, and this week I hope everything - finally - will properly work. What disturbs le is that when I wanted to push some fluid back from the bleed output of the slave cylinder to the reservoir of the Master cylinder, it was nearly impossible, so much the resistance was strong. I had to move the clutch fork. I'm convinced the TAE part will work.

[manovlov]

Hy

I should get my new ATE slave cylinder thirsday. I will reverse 2 hoses, that could explain why it's impossible to me to feed the reservoir by the slave cylinder with a syringe. It's the only solution I see that could explain what happened. If it's my mistake (that probably should be) I will inform the seller. Newbie, honest.

Boards come from Volvo Parts Webstore

A how hoses are plug.jpeg (40.21 KiB) Viewed 1098 times

B reversing hoses outputs.jpg (42.22 KiB) Viewed 1098 times

[manovlov]

Okay.

I've found the issue : I have inverted hose 1 and 2. That's the reason why I was unable to bleed back the air in the MBC. I will correct my installation tomorrow afternoon and tell you if I've managed to clear the issu.

Manov

PART_1599736603355 copie.jpg (354.08 KiB) Viewed 1074 times

[manovlov]

The master cylinder is out.

[volvolugnut]

The sweet sound of success is even sweeter after the struggle. I hope this translates well.
volvolugnut

[manovlov]

Yes, for sure.

I am beginning to understand the difference between repairing and restoring. On the other hand, all the parts are original, some of them frozen in rust. Actually, what would be cool is a long weekend with my buddies from MVS, around a huge barbecue, a few beers, one or two toolboxes, and exchange, information, learning.

For the 20 years of MVS maybe...

[manovlov]

Help Wanted !



Well, hy Boyz ! Manov on the air.

So next episode : the master cylinder is new (Ate), the clutch pedal cylinder is new, the slave cylinder is new.... But still doesn't work.

I pump about fifteen times and always the same result: the piston of the clutch receiver extends, my clutch pedal ends up pumping in a vacuum and remains at the bottom of the crankset and it's impossible to release the piston of the clutch receiver.

I confess, I don't understand anything. I start to ask myself if it was really necessary to change the master cylinder and slave cylinder (this one for the third time...).

I must be wrong in the way hoses are plugged. I will reverse the hoses from the pedal and the slave cylinder.

Burger quizz.png (99.58 KiB) Viewed 1051 times

Does someone has a board on the right way to install the circuit ? Or any idea ?

Manov

Edit :
I found this : it confirms that I was wrong with the hose that comes from the pedal.If the hose has been replaced at its right place on the picture.

clutch pedal.png (1012.89 KiB) Viewed 1047 times

[manovlov]

Hy,

Here is the explanations about the way to plug hoses on the reservoir, by the Volvo dealer mechanic. He explained to me that he did a master cylinder replacement recently, on a 850 and took some pictures before to start to unscrew anything. He gaves me the tips to bleed correctly the hoses. He plugs the bleeder of the slave cylinder to the bleeder of a brake piston and use the brake pedal to bleed all the air correctly. To those who could find this tips useful.

Volvo dealer explanation.png (101.3 KiB) Viewed 1036 times

Manov

[manovlov]

Finally, the clutch works.The mounting shown below is the right one. For those who could have need that information. Thanks for your support Guys, you're amazing !

Manov