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MG Midget and Sprite Technical - Switching to silicone brake fluid

Can someone explain what would be involved in switching to silicone hydraulic fluid from glycol? Proper flushing? Rebuilding a master cyl. this week. Thanks in advance.

Been a while, missed you guys.
CJCharvet

CJ - Complete flush of the system to get all the old glycol fluid out of it. Replace all rubber (neoprene components). Fill with silicone fluid slowly so as to not get a lot of bubbles in it. Bleed as normal. Cheers - Dave
David DuBois

So would one have to replace all seals in the system? Sounds expensive to me. I had thought about doing it as i'm sick of brake fluid knackering me paint up.
Tarquin

Changed to silicone in 97. Didnt flush nor replace seals and no problems since and that is on my daily driver (XR3i) Both sprites have it as well.
Alan Anstead

I think it's switching back that requires a change of all the seals
Will Munns

I'm getting ready to do my rear cylinders, and am very interested in going silicone.
I'm very slowly loosing fluid, so I suspect the rear. The fluid that I have is Castrol, and even after a full flush it soon gets very dark colored. Why?
Phil 'midgets getting a silicone implant'
Phil

Phil, sounds like rust in yout lines or cylinders.

Anyone else want to add their .02 on replacing rubber? If that's the case I'll probably stick with glycol. Thanks for the replies!
CJCharvet

my question is why?

fil it up and for a road car flush once a year max (once every 2 jears is fine too)

filling isn't that hard is it? even with the combined mc it works fine with a little funel

and dot 4 is fine for a road car

so the question is why
Onno Könemann

CJ,
For one more opinion, you might consult Barney Gaylord's website, MGAGuru.com. Specifically, http://www.mgaguru.com/mgtech/hydraulics/ht115.htm
David "no silly con jobs here" Lieb
David Lieb

Well....After the archive search and your excellent input. looks like I'm going to stick with the good old paint removing glycol.

Cheers,
Courtney "Why do I only ask heated bi-partisan questions?" Charvet

CJCharvet

Because it is so much fun!
David "life is NOT a spectator sport" Lieb
David Lieb

Staying away from silicone fluid = one of the better decisions you've ever made.

It's not suited for any high performance application and can cause more problems than it solves. Some people have had no problems but then again more people have no problems with regular fluids.
Daniel Thirteen-Twelve

I am running silicone in my car for 8 years now and besides 2 brake switches no problem whatsoever. I did however replace the fuellines with braided ones so the fact that silicone fluid can be compressed a little more is compensated for.

I decided the go silicone after a complete rebuild of my car involving new brake and clutch parts.

Bas
Bas Timmermans

I have been DOT 3, DOT 4, DOT 5.1 brake fluid for about 28 years and I've only had to replace a brake switch once.

I have braided steel lines so still have a better pedal than a car with silicone fluid and braided steel lines.

I do need to change my fluid an annual basis because it absorbs water but then again that's safer than the water remaining free water in the fluid that can turn to steam.

I haven't invalidated any warranty with the manufacturer of my braking system components.

Daniel Thirteen-Twelve

Sorry for contributing my 2 cents
Bas Timmermans

My dad had a B he used silicon in and had really good results.

I finally got my Master back together. Found a shop with Castrol LMA so thats what I went with.

Brake master cylinder: one of the only items on our little cars that is easier to put together than it is to get apart!
CJCharvet

As far as I know, there is only one good silicone brake fluid and that is Castrol SRF. However, reading the info on it again, I am actually doubting that it is actually silicone....!

http://www.opieoils.co.uk/p-740-castrol-srf-racing-brake-fluid.aspx

At over £52.00 per Litre, it should be something special....!

Mark.
M T Boldry

And it only lasts eighteen months Mark! £35 from Zip north if that helps.
Cheers John
JOHN HALL & JULIE ROBERTS

This thread was discussed between 26/06/2009 and 07/07/2009

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.