Porsche Enthusiasts Club Forum

Hi all

I have fitted both the master and slave cylinders and set the master rod length.
The with the clutch pedal in the fully disengaged position the arm at the return spring position is touching the bulkhead.
I don’t think this is correct!
The new master cylinder rod is a loose fit into the hydraulic cylinder not (not physically attached).

Is this wrong any advice would be great.

Regards

Mark

I think that I may need to rebuild the old master cylinder, looking at the new and old side by side the operating rod of the new item although physically the same, you can pull the new rod out of the plunger (it is not retained!
The original fitted item operating rod iis retained and cannot be pulled out.

I have a rebuild kit on order for £22 from WPO.

Fingers Crossed!

Regards

Mark

You need to check the bore of the old cylinder carefully any wear or rust will ruin the new seals

When I rebuild them I whizz a mini bore hone in them to clean them up,

The rod should be retained in the cylinder with a clip

Thanks Waylander, Could you recommend a mini bore hone that will suffice for this job.

Regards

Mark

this should do both the master and slave,

https://www.ebay.co.uk/itm/19mm-62mm-Bo ... SwOW9Z4VNT

there are other options like Flex-Hone but they are really expensive

https://www.ebay.co.uk/itm/3-4-19mm-Fle ... xybi9Rc77Z

Thanks again Waylander any advice on the honing process.

Regards

Mark

Go slow with a battery drill, your not trying to rebore them just smooth and clean the surface

Use some light oil as lube, and brake cleaner to wash it out after

Struggling to bleed this SOB!

I fitted new seals to the master fitted all new hoses topped up the reservoir.

I set the length of the rod to 112 mm (taking into account the bulkhead 3mm)

I am using a Gunson bleed kit off a tyre pumped to the max of 20 psi.

The pedal wants to go down to the floor due to no opposing hydraulic pressure so I have propped it up!

I can’t get fluid from the master (by cracking the discharge pipe).

I am beginning to pull out what little hair I have left!

My logic is telling me the refurb of the master has caused a blockage.

At the same time I am not happy with this gunson thing.

Could anyone offer me some sage advice?

Regards

Mark

You must have an air lock that you can’t get free or the cylinder is not allowing fluid in, or you have not assembled in the correct order

They are a pain in the add to bleed, I ended up reverse bleeding mine with a pump oil can,

If your cracking the pipe at the master end and no fluid is coming out even with the pressure attached something is seriously wrong

If the piston is at the bottom of the bore, it won't bleed. has the pedal pushed it down and left it there?

Well I have had little time to work on this issue until today.
I propped the clutch pedal up so it doesn’t smash everything through the bulkhead with the assisted spring (as factory set)
I tried reverse bleeding with a new oil can and managed to push loads of air out then it stopped!
The pedal still has no feel of hydraulics about it and the pedal still wants to slam through the floor!

I think my next move is to get a new master from Frazier part to eliminate that part.
I am not convinced of the 109 +3 mm lenght for the set length.

I can’t see any return spring that opposes the assister spring but I really feels like one should be fitted!

Can any body comment on where may lay the problem.

I will provail over this!

Regards

Mark

As previously mentioned the piston is either stuck at the bottom of the bore or your refurb just didn't work. I recently replaced both slave and master. The master was totally shot.
Bleeding was a real pain, that tiny bleed nipple in a very awkward location and the fit was so poor when you cracked it open fluid was running up the threads. I tried ptfe tape without any luck then pinched an idea from the Rennlist 993 forum where a guy had fitted a remote bleeder. A local shop that does a lot of bike stuff made up a flexy pipe for me with 7mm banjo at the nipple end and a bleed nipple at the other. I made a small angle bracket and fitted it next to the fluid reservoir. I used the Gunson pressure bleed with the pedal up, then tightened the bleed and did a few small strokes of the pedal to release any air bubbles, repeated the pressure bleed job done. That assister spring is like a mouse trap when it goes over center nearly took my fingers off.

Thank you endoman you have given me an extra nudge in the right direction, I have a brand new master coming from frazerpart, I am interested in the remote bleeder idea could would you have the length of the bleed hose?

Regards

Mark

It worked out around 1 metre, best to work out best place to fit bleeder for your car and measure it with some of that flexible curtain rail or a length of garden hose, avoiding the exhaust. I'll post a pic of it in situ. I did the same for my 993, HAL made that, great service, chatted to a guy over the phone and they supplied a banjo bolt and a couple of copper washers. The photo is the 993 one with an MPL slave cylinder.
The 944 remote bleed nipple is from the States (not metric) it came with bulkhead fitting and the angle bracket. You just need to specify which fiting you want. If you ever consider fitting braided hose HAL (far superior to Goodridge and made in UK) are great to deal with but stick with std rubber on rear as the braided ones don't like to be twisted.

Just would like to say thanks for all the help, I change the master with new.
Reverse filled the system and the bled the system using a brand new sealey vs820.
Then adjusted the pedal to length.
I think the Gunson was some how air locking the system rather than helping.
What a joy!

Thanks

Mark