I have just been so so disheartened

[WorAl]

OK, many of you may know that I am designing a new slave cylinder.

All was going well, up to the point of actually sending my drawings for machining. Material has been purchased and they were just about to start when I had a call from the people who were going to supply my seals. They dont produce them in the material I require - I mean, what the fk is going on here?? I specifically asked for a certain size, a certain material, temperatures etc etc and they said "yes, no problem" only to tell me at the 11th hour "oh, sorry no we dont stock that item" - stop press, dont machine I now have to re-design it all again to accomodate different seals. fking useless wkers.

ETA: I have actually bought the material to produce the parts, so going to be £100 out of pocket no matter what. PRICKS

Now im not going to be able to get my car on the road by the 31st for the Whitby Goth run - fking gutted doesnt describe it.

I actually feel like selling the car now as the original seals are st and will always have the same problem - can anyone confirm what the seals are made from? i've been told neoprene, which is no good at all in any oil, never mind hudraulic oil.

Edited by WorAl on Tuesday 13th October 10:00

[Cooky]

I'd be very surprised if neoprene/buna nitrile is used as OE (however we are talking TVR so anything is possible ), more likely to be viton, but if upgrading I'd be tempted to go for EPDM with a PTFE backup ring as this gives the best compatibility results for Hydraulic fluid. Be careful when selecting the sure hardness as the usual 70 is a little soft and uprating to 90 may be a little too hard.
HTH

[WorAl]

yeah I think more likely Viton too, but had word from one respected TVR specialist that it is Neoprene, maybe why mine disintegrated after 8 month.

[Cooky]

WorAl said:

yeah I think more likely Viton too, but had word from one respected TVR specialist that it is Neoprene, maybe why mine disintegrated after 8 month.

YHM

[WorAl]

cheers phil, be in touch this afternoon

[JensenA]

I feel for you Al, it's all indicative of why Britain is slipping down a slippery slope into nothingness. Have a go sourcing them from China, do a google search, theres plenty of Sourcing from China type sites. Good luck.

[SI-PEN]

I must be missing the point here? My 4.5 had the original slave and seals for 9 years and 30,000 miles. Perhaps the newer material being used is crap but the older stuff must have been fine.

Anyway, sorry for your pain!

[AlexH22]

Chin up, your pain could reduce other owners suffering the same fate, just think how much you could improve the quality of other people's lives with tvr's stricken in their garages.

I feel for you having to re design and being out of pocket, maybe that can be clawed back once you have a better set of seals to sell on.

Dont give up.

[ridds]

Cooky said:

I'd be very surprised if neoprene/buna nitrile is used as OE (however we are talking TVR so anything is possible ), more likely to be viton, but if upgrading I'd be tempted to go for EPDM with a PTFE backup ring as this gives the best compatibility results for Hydraulic fluid. Be careful when selecting the sure hardness as the usual 70 is a little soft and uprating to 90 may be a little too hard.
HTH

tbh I'd though EPDM would be the last thing you want to put in there.

EPDM - Ethylene-Propylene

EPDM is an excellent choice for hot water (300°F / 100°C) and steam (350°F / 175°C) applications. It also exhibits good resistance to detergents, potassium hydroxide solutions (potash), sodium hydroxide (lye), silicone oil and greases, polar solvents and diluted acids. The wide range of compatibility makes EPDM a great choice for almost any sealing application; however it does not stand up well to mineral oil products.

I'd go with a Viton and use a double seal design as per the Raceproved set up. Use a PTFE backing/support piece to prevent scoring and move from a Lathe cut seal to a round O-ring due to improved dynamic sealing. My guess was that the lathe cut seal was kinda cheap way of providing the support of a PTFE spacer. I'd also get the seals sized correctly for the gland volume as I'm pretty sure they're not at the moment.

Also, there are different seal materials out there, my last seals had melted, they were just gooey mess when I removed them.

The second hand cylinder I've just got is showing signs of chipping to the leading edges of both seals.

[Mr.Cerbera]

WorAl said:

.....the Whitby Goth run .....

Hmmmmmmm, groin warming to the sound of that

[WorAl]

Mr.Cerbera said:

WorAl said:

.....the Whitby Goth run .....

Hmmmmmmm, groin warming to the sound of that

Its superb.....especially if you like the look

Last year was a run over the North York Moors before we headed toward Whitby.

[WorAl]

ridds said:

Cooky said:

I'd be very surprised if neoprene/buna nitrile is used as OE (however we are talking TVR so anything is possible ), more likely to be viton, but if upgrading I'd be tempted to go for EPDM with a PTFE backup ring as this gives the best compatibility results for Hydraulic fluid. Be careful when selecting the sure hardness as the usual 70 is a little soft and uprating to 90 may be a little too hard.
HTH

tbh I'd though EPDM would be the last thing you want to put in there.

EPDM - Ethylene-Propylene

EPDM is an excellent choice for hot water (300°F / 100°C) and steam (350°F / 175°C) applications. It also exhibits good resistance to detergents, potassium hydroxide solutions (potash), sodium hydroxide (lye), silicone oil and greases, polar solvents and diluted acids. The wide range of compatibility makes EPDM a great choice for almost any sealing application; however it does not stand up well to mineral oil products.

I'd go with a Viton and use a double seal design as per the Raceproved set up. Use a PTFE backing/support piece to prevent scoring and move from a Lathe cut seal to a round O-ring due to improved dynamic sealing. My guess was that the lathe cut seal was kinda cheap way of providing the support of a PTFE spacer. I'd also get the seals sized correctly for the gland volume as I'm pretty sure they're not at the moment.

Also, there are different seal materials out there, my last seals had melted, they were just gooey mess when I removed them.

The second hand cylinder I've just got is showing signs of chipping to the leading edges of both seals.

If used in a dynamic seal, O-rings will always leak a small bit of fluid past.

EPDM is used in brake systems all the time and most of the rubbers are EPDM, Hoses, Seals etc. The only problem I may have is the temperature. Im just experimenting for now anyway.

I've also heard of the Raceproved Cylinder leaking.

I have researched this you know, its not just a slap dash effort, have just been let down by one certain supplier. Have found someone else to supply them now, so things looking good again, however I may be out of a job as I spent most of my working day yesterday on the phone looking for a new supplier

[ridds]

Don't get me wrong not picking at your work just chucking a few ideas into the pot.

Another factor not covered by the original seal set-up is the complete lack of any sort of dust seal to prevent clutch dust ingression into the cylinder/seal area.

[WorAl]

sorry I came across as a bit of an arse this morning.....it was morning after all.

I am having one company look into the use of a different material for the seals, temperature ranging is good but he's not 100% about suitability in these fluids.

I have looked at stopping the dust entering the cylinder but not sure there is much can be done about that apart from put some sort of condom over the whole lot as you will always get some sort of dust ingress along the drive shaft and into the cylinder.

WorAl said:

condom

Edited by WorAl on Wednesday 14th October 17:54

[ridds]

It must be a failure mode though as Vauxhall and the like wouldn't have included them on theirs if not.

e.g.

[WorAl]

is it the green cover that you are talking about here?

If so, you couldnt have that on the cerb slave, well you could but would be awkward, I tried a design for a double seal on the outer cylinder to be some sort of dust cover/preventer, but there isnt enought meat on the bell housing to accomodate this. I thought you meant down the drive shaft?

I also tried to include aditional bolt holes around the flange so that it fastens in more than 4 places as this is also a poor design, but because of the way the bell housing is cast and the inlet/bleed ports are positioned you cant, shame really unless I design a new Bell housing

Edited by WorAl on Thursday 15th October 16:11

[Cooky]

Enjoyed the chat this afternoon Al, glad things are lookin' up for you mate. Just had an email back from one of our seal suppliers and he states he will send a couple of freebie samples of their latest 'poly' seal in a V cup 5.75mm section with a 0.25mm PTFE lining seal to be used as an additional option if required.

max pressure 5000 psi
advised working temp not to exceed 200C
fully compliant with mineral based and synthetic hydraulic fluids

so looks like this may be a reasonable alternative to what you have sourced. I'll post you them along with catalogue/ spec. sheet as soon as they land.

[WorAl]

Cooky said:

Enjoyed the chat this afternoon Al, glad things are lookin' up for you mate. Just had an email back from one of our seal suppliers and he states he will send a couple of freebie samples of their latest 'poly' seal in a V cup 5.75mm section with a 0.25mm PTFE lining seal to be used as an additional option if required.

max pressure 5000 psi
advised working temp not to exceed 200C
fully compliant with mineral based and synthetic hydraulic fluids

so looks like this may be a reasonable alternative to what you have sourced. I'll post you them along with catalogue/ spec. sheet as soon as they land.

Just sent PM mate.

Would like to have a look at those seals see if they are any better, check email for new sizes though as had to make some changes.

[Cooky]

Goddamn design engineers...should be drowned at birth

no worries mate

[WorAl]

well thats that job fked, not going on goth run because of fking twisty tt royal fail workers. bunch of s!!!!