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Clutch fluid V8 250 manual

Posted: Sat Jun 09, 2018 5:50 pm
by Sydsmith
I am sure I have seen this question asked before but a search brings up a load of SP250 clutch stuff and nothing on the V8 25o

My manual V8 250 has been run regularly on dry days this winter, but on the day I intended to take it out for a run, the clutch pedal first refused to budge, under a bit of pressure it went suddenly to the floor and went all floppy.

I suspect seals and have decided to replace both the slave and master cylinder seals flush the system out and refill with synthetic fluid, but is that wise and which one should I use? I have plenty of Dot 4, is it suitable?

Re: Clutch fluid V8 250 manual

Posted: Sun Jun 10, 2018 10:47 am
by buckfield
Hi, I use dot 4 on braking systems and dot 3 on clutch etc, although dot 4 will do both ,only thing to mention is if the new seal kits are not as original, but they should be. just don't use dot 5 silicone. Tony

Re: Clutch fluid V8 250 manual

Posted: Sun Jun 10, 2018 2:44 pm
by Sydsmith
Many thanks Tony, as always the forum comes up trumps, exactly what I needed to know.

Was thinking Manners for the seals, so they should be to original spec. Syd

Re: Clutch fluid V8 250 manual

Posted: Sun Jun 10, 2018 8:25 pm
by NickDeAth
Just for my curiosity why not use DOT 5, I've always been given to understand it is the better option because it is not hygroscopic.

Nick

Re: Clutch fluid V8 250 manual

Posted: Sun Jun 10, 2018 9:16 pm
by buckfield
Hi yes you could use dot 5, lots of info out there about differences with pedal feel etc, although that's to do with braking systems, and having a clean system and the neoprene seals, but I use traditional fluids as I drain my brakes and clutch systems every 3 years and renew the fluid. used to be an issue with silicone fluid but maybe it's now a myth? Tony

Re: Clutch fluid V8 250 manual

Posted: Sun Jun 10, 2018 10:19 pm
by Sydsmith
Nick. I have yet to strip the system but am assuming that I have problems with fluid standing over winter that has damaged either the seals or barrels.

Having had problems with corrosion from mineral fluid in the past, the principle reason I intend to drain flush and refill the system with synthetic was to avoid that again. I have enough Dot 4 in a new sealed container left over from changing the brake fluid last year and am assuming Dot 4 will avoid the hygroscopic problem with the clutch. Are you saying Dot 4 is hygroscopic?

Re: Clutch fluid V8 250 manual

Posted: Mon Jun 11, 2018 12:24 am
by buckfield
Hi, syd, are you confusing synthetic with silicone? as all non silicone brake fluids are synthetic now, dot3 dot 4 dot 5.1 etc which are different from silicone dot5. hope this clears it up? tony. http://forums.mtbr.com/brake-time/silic ... 32808.html

Re: Clutch fluid V8 250 manual

Posted: Mon Jun 11, 2018 8:58 pm
by Sydsmith
Thanks Tony, very useful stuff on the subject.

We are off to Ireland for a couple of weeks and will tackle the beast when I get back, something not to look forward to perhaps. Syd

Re: Clutch fluid V8 250 manual

Posted: Mon Jun 11, 2018 9:06 pm
by buckfield
Hi Syd, have a great time in Ireland, great country to see. Tony :mrgreen:

Re: Clutch fluid V8 250 manual

Posted: Mon Jun 11, 2018 9:37 pm
by faeton
Back in the the days before zero tax for classics I used to tax my cars for the summer months only ..Living in a particularly wet part of the country I had lots of problems caused by water absorption in brake fluid [hydroscopic] damaging cylinders ,Particulary the tandem master cylinder on a Frogeye Sprite, where fluid leaked and ran down the body ruining the paintwork. I decided to change to Silicone . That was over 25yrs ago and since have never had a problem . Another advantage silicone doesnt harm paint.
I have used Silicone fluid in my SP250 since rebuild 20years ago and have never had to change any rubbers in either brakes or clutch.
The American military endorse and use Silicone fluid in all their vehicle . I understand that it is not suitable for racing or high speed use but as most of us drive our old cars with care I dont see any problems .

Dave


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