Castrol SRF

I had the brake fluid changed a couple of months ago and Turbo Technics filled it with standard fluid. They didn’t no it had SRF in it so they didn’t put it back in. Its booked in at Turbo Technics next week so wanted to get it changed while its there. Where is the best place to get it from and how much will i need to buy?



It’s sold on 1 litre cans, which will be plenty for the job in hand. Expect to pay about �43 (yes �43) for the 1 litre can. Don’t know who sells it locally to you, but I know that Demon Tweeks stock it. SRF should be changed every 18 months or so, because it’s hydroscopic.


PS Why is it going back to TT ?

Our place stocks SRF and we charge �20 per litre. I don’t like sending this kind of thing through the post though as I have had a few issues in the past. Where are you based?



Where are you based - as I always prefer to keep a couple of cans in stock?


Sean, somebody going to Croft will live near you and I think a bulk order is highly likely at that price!

Pesky, doesn’t it go off (/suck in water and become bad)? Therefore isn’t buying too much if you’re not going to use is a bad thing?



Ian is quite right - can you attach a trailer to your Exige & bring a load of SRF to Croft, please?

Ian - yep it’s “hydroscopic”, but as far as I know, that’s only a problem once the seal on the tin is broken. Sean, am I correct, please?

Hi Guys,

We are based just outside Birmingham. Nearest motorway junction is Junction 2 of the M5. I am out of the country at the moment, but am deffo looking at coming to Croft and meeting all of you guys.

Yes SRF is hydroscopic. Which basically means it absorbs water. A sealed container will obviously keep for ages, but I have to say that I like to use up the contents of an open bottle within a few months.

You will note that most brake fluids have a wet and dry boiling point. The wet boiling point is measured when the fluid is saturated and can’t absorb anymore water.

Don’t however think that the fluid absorbing water is a bad thing. It is indeed a very very good thing. I have known people that use silicon fluids (non hydroscopic) have huge accidents, because the non absorbed water in the brake lines simply boiled leaving zero brakes!!!

Let me know who wants what at Croft and I will bring some along.




Where exact ? - My UK base is Halesowen so just off Junction Three and I certainly would like a 100 quids worth …

We are between Blackheath and netherton on the Doulton Road trading Estate.


Im based in Fillongley near Coventry and would be interested in some at that price. When can i pick some up then? Its going back to Turbo Technics because they do everything on the car and im getting the charge cooler changed and having it serviced aswel.


Perfect … can we turn up and get it at that price ?

Yeah no problem guys.

Check out our website (which I apologise now for it not being finished) for a map. Call me on my mobile 07967 662294 from Tuesday of next week onwards.


Perfect Sean

OK - I can be the SRF bringer if anyone wants a few litres - let me know and I’ll arrange a pick up from Sean



How much flushng out of the old stuff do you have to do with SRF ??.. will it mix okay with my dot 4 Castrol RS… i mean i’ll flush it out of course but wouldn’t be intending doing much more to purge the system other than draining it out one end while i fill up with SRF at the other.

When ya going Andy?



You’ll have enough with a 1 litre tin. Did mine the other day, still have about 200ml left.

Andy - please would you pick up a couple of tins (for me & Russ) - ta. Drop me a line with your address, so I can send a cheque

cheers Pesky

i didn’t quite explain my worry too well i don’t think…i was meaning that if you don’t completely purge the system of the old fluid before filling SRF into it will that be a waste of time ?? ie will the SRF mix okay with dot 4 (or super dot 4 in my case… whatever that is )

I suspect it will be okay but need some confirmation before i go spendin my money… can’t let too many moths away you know…

i guess you started with SRF in there in the first place ?


Had SRF in it pre Honda. (Whilst in the workshop they fitted Nitrons, nylatron bushes & re-plate the wishbones). Car was returned to me filled with brake/clutch fluid which they use in the clutch system of the Tyrell F1 car they run. Whilst this is fine on the road, it ended up with a spongy pedal on track at Anglesey last Sunday. Pedal feel returned to “normal” on the way home. But, we relaced the fluid with SRF last week - I was in charge of pressing the brake pedal , so that’s how I know that 1 litre will be enough to thoroughly drain the old stuff out as well

Go for it, you tight Jock

I best check how much I have in stock when I get back lol. I am sure i have at least 10 litres. If not a re-order will only take a week or so.