the new metal master cylinder - Page 39

roverbarmy · 19th January 2015, 12:57

One other point to note is that the solid rubber circular seal for the screw top on the reservoir could inhibit the venting of the reservoir by blocking the vent hole. This could possibly cause a back pressure on the reservoir (due to the venting of the larger bore end of the piston via the rear hole in the reservoir base) and push fluid past the pedal end seal when the pedal is pushed. These are merely opinions on my observations and may not be facts in operation.

Another leak source could be the joint between the brass inner sleeve and the machined aluminium block. The joint between the two is under constant pressure at the outlet end when in use and any leakage could track back along the joint between the two metals and appear at the pedal end (as if the rubber seal was leaking. I don't know if there is any sealing between the brass lining and the aluminium block ( dissimilar metals?) other than the pin that holds it in place or if it is just a flush/interference fit?

Again, just trying to come up with suggestions/observations to try and help.
Mike

HarryM1BYT · 19th January 2015, 13:38

Quote:

Originally Posted by roverbarmy

One other point to note is that the solid rubber circular seal for the screw top on the reservoir could inhibit the venting of the reservoir by blocking the vent hole. This could possibly cause a back pressure on the reservoir (due to the venting of the larger bore end of the piston via the rear hole in the reservoir base) and push fluid past the pedal end seal when the pedal is pushed. These are merely opinions on my observations and may not be facts in operation.

I think that point has been raised before and I agree completely. Lack of proper and adequate air venting, will set up vacuum and pressure as the pedal is pressed, as also can variations in temperature.

Those complaining of leaks - do check the vent hole is clear.

It was one of the things I made a point of checking on installing mine and I still have no leakage.

roverbarmy · 19th January 2015, 15:24

Quote:

Originally Posted by HarryM1BYT

do check the vent hole is clear.

It's not just the vent hole. It's the fact that a full disc rubber seal (as supplied) will itself form a seal over the vent hole when the cap is screwed onto it. A rubber rim seal would, in my opinion, be preferable. There may be a small amount of upward splash from the rear seal vent (the one nearest the pedal in the bottom of the reservoir), so a splash guard may be necessary.

to avoid fluid loss (via the cap vent hole).
Mike

roverbarmy · 20th January 2015, 14:04

Quote:

Originally Posted by roverbarmy

Another leak source could be the joint between the brass inner sleeve and the machined aluminium block. The joint between the two is under constant pressure at the outlet end when in use and any leakage could track back along the joint between the two metals and appear at the pedal end (as if the rubber seal was leaking. I don't know if there is any sealing between the brass lining and the aluminium block ( dissimilar metals?) other than the pin that holds it in place or if it is just a flush/interference fit?

Mike

UPDATE.
I have disassembled the brass sleeve from the aluminium casing and it has a series of circular seals between points of possible leakage (ie the two ends, the delivery and vent holes) so that should eliminate any leaks from the joint between the aluminium and the brass- or will circular shaped seals resist full pedal pressure enough?
Mike

First_damned · 25th February 2015, 20:52

Have the issues with this now been fully resolved?

Ched · 26th February 2015, 09:36

I've heard nothing to suggest otherwise and I'm still bleeding mine every week.

Woodsie · 26th February 2015, 09:52

Quote:

Originally Posted by Ched

I've heard nothing to suggest otherwise and I'm still bleeding mine every week.

Me too, except I do it every 3 weeks as I do not use the car much. By the way, mine was received with no seal or gasket under the resevoir cap and fluid seems to be escaping from this area. I have PM'd Andy about this but as yet have not heard from him.

Regards Rich

wullie480 · 26th February 2015, 11:21

I change the master,slave & clutch in the wifes in october last year, I fitted the full metal master & I have found it to be leaking last week so Andy has said he will send some new seals, so awaiting there arrival so I can get them changed over & hopefully that's it sorted for good.

Organiser · 26th February 2015, 13:27

Mine's stopped leaking now.......

Because it's in a cardboard box of old spare and replaced parts in my workshop..

Replaced with a Tazu Mark 1.

Tom.

First_damned · 26th February 2015, 13:41

Quote:

Originally Posted by Organiser

Mine's stopped leaking now.......

Because it's in a cardboard box of old spare and replaced parts in my workshop..

Replaced with a Tazu Mark 1.

Tom.

I gave mine away, what a nightmare it was. The new seals make no difference too.

Luckily I was sent a replacement mk1 and I purchased a custom flexi hose, no problems ever since fitting it.

19th January 2015, 12:57	#381
roverbarmy This is my second home Roverless + 1.7D Sportage Join Date: Aug 2014 Location: East Norfolk Posts: 7,058 Thanks: 729 Thanked 2,021 Times in 1,449 Posts	One other point to note is that the solid rubber circular seal for the screw top on the reservoir could inhibit the venting of the reservoir by blocking the vent hole. This could possibly cause a back pressure on the reservoir (due to the venting of the larger bore end of the piston via the rear hole in the reservoir base) and push fluid past the pedal end seal when the pedal is pushed. These are merely opinions on my observations and may not be facts in operation. Another leak source could be the joint between the brass inner sleeve and the machined aluminium block. The joint between the two is under constant pressure at the outlet end when in use and any leakage could track back along the joint between the two metals and appear at the pedal end (as if the rubber seal was leaking. I don't know if there is any sealing between the brass lining and the aluminium block ( dissimilar metals?) other than the pin that holds it in place or if it is just a flush/interference fit? Again, just trying to come up with suggestions/observations to try and help. Mike __________________ Oil in my veins!

26th February 2015, 11:21	#388
wullie480 This is my second home 1 Join Date: Dec 2010 Location: Banned Posts: 5,195 Thanks: 528 Thanked 1,022 Times in 786 Posts	I change the master,slave & clutch in the wifes in october last year, I fitted the full metal master & I have found it to be leaking last week so Andy has said he will send some new seals, so awaiting there arrival so I can get them changed over & hopefully that's it sorted for good. __________________ [SIGPIC][/SIGPIC]

26th February 2015, 13:27	#389
Organiser I really should get out more....... ZT-T+180 Auto & ZT-T+1.8T in Trophy Blue, ZT-T CDTI+135 Auto in Ignition Blue, ZT-T+190 in Typhoon, Join Date: Mar 2013 Location: Walsall Posts: 2,035 Thanks: 1,435 Thanked 600 Times in 467 Posts	Mine's stopped leaking now....... Because it's in a cardboard box of old spare and replaced parts in my workshop.. Replaced with a Tazu Mark 1. Tom. __________________ Remember a Typhoon is for life not just Christmas! Now plus the Yellow Peril.

25th February 2015, 20:52	#385
First_damned Posted a thing or two Rover 75 Connoisseur CDTi Join Date: Aug 2013 Location: Birmingham Posts: 1,272 Thanks: 267 Thanked 100 Times in 93 Posts	Have the issues with this now been fully resolved?

26th February 2015, 09:36	#386
Ched I really should get out more....... MG ZT V8, MGZT 135 derv ,MG TF 135 Join Date: Dec 2011 Location: Romsey Posts: 2,296 Thanks: 553 Thanked 573 Times in 385 Posts	I've heard nothing to suggest otherwise and I'm still bleeding mine every week.