Silicone brake fluid for a Fulvia

[HF_Dave]

I  just took out my Fulvia from storage and the brakes are binding again  . I spoke to someone about putting silicone fluid in instead of the normal fluid, apperantly it stops the calliper so from rusting an causing the Pistons in the calliper to seize.  Has anybody tried this ? I looked it up on the internet and came across various comments ranging form fantastic to " I'll never put this stuff near a car  " . Has anybody any thoughts on this . Thanks David 

[lancialulu]

Dave

I have run this on 3 Fulvias for over 10 years now. I still own 2 of them. I had one problem in that time with a seal on the front caliper which could have been caused by the seal reacting to Silicon fluid. All Brake systems were Girling. I would say you can only really use this if you are totatally rebuilding the brake system i.e. There is no dot 4 fluid as they do not mix.

The fluid stays a nice purple colour over the years which looks nice in the m/c!

No doubt others have different views.

Tim

[HF_Dave]

Thats interesting . I was looking at instructions on the web and it is suggested to flush the system with Meths in order to remove all the old fluid . using a compressor to force it through the system . I rebuilt the whole thing 5 yrs ago with copper lines and new flexi hoses . Its a pity I didn't know about that then . Now another question, has anybody flushed the system before ? Thanks David

[HF_Dave]

Another Question . To have the callipers re-built professionally , can someone recommend  a good repair crowd . I got a quote from Omicron which includes er-sleeving the calliper and re-plating the pistons . I got another quote about half the price but they dont re-plate the pistons . Thanks David 

[lancialulu]

Try  http://www.biggred.co.uk/

Re flushing I did not replace the solid lines just rebuilt the calipers and new flexies. Flushed through with a bottle of silicone before the final bleed IIRC.

[nistri]

Regardless the type of brake fluid, brake pistons can seize up (at least partially) when the rubber dust covers are damaged or lifted so that water/dirt can enter through them and block the piston movement. This has nothing to do with the moisture (or lack of it) in the brake fluid that does not have contact with them. Dust covers are also ruined by strong heat such as generated by strong braking. Of course, rust (via the  brake fluid) can also eat away the cylinder wall, the piston and particularly the bottom part of the cylinder well. This latter type of problem is prevented by changing the standard brake fluid every year. Andrea

[Jaydub]

We always use Past Parts Ltd, Bury St Edmunds. They rebuild/refurbish most things classic, cars. trucks etc.
Personally, I wouldn`t use silicone fluid as we have had instances of seals swelling. As Andrea said, flush regularly and use Dot 5 fluid. If it has had silicone in it you might have to reseal anyway and just bleed out the old fluid.
But others may say differently according to experiences.
John

[neil-yaj396]

Try  http://www.biggred.co.uk/

Re flushing I did not replace the solid lines just rebuilt the calipers and new flexies. Flushed through with a bottle of silicone before the final bleed IIRC.

Just to add a balancing view, Big Red did a bad job on some rear Beta calipers of mine. They actually fitted the hand brake mechanism upside down, leading to a complete failure after I had sold the car.

They were well recommended on here and the Betaboyz Forum prior to that though.

[fay66]

Unfortunately S--t happens sometimes, someone probably had a bad day, but not a great deal of help to you Neil or the person you sold the Beta too, did they do the honourable thing and put matters right.

Brian
8227

[neil-yaj396]

Unfortunately S--t happens sometimes, someone probably had a bad day, but not a great deal of help to you Neil or the person you sold the Beta too, did they do the honourable thing and put matters right.

Brian
8227

The new owner had the invoice for the work, but I don't think he followed it up.

[lancialulu]

Today I got round to replacing the Silicone Brake fluid in my Sport 1600. I think this has not been changed since I fully rebuilt and commissioned the brake system back in 2007.

I was curious as to why the purple colour of the fluid in the master cylinder had turned transparent over time.

Starting at the back near side using gravity and some 1-2psi pressure  assist a "master cylinder like" volume of clear liquid came out followed by new purple fluid. All the rest of the cylinders produced purple fluid so I assume the fluid lost its purple only in the master cylinder.

Strange but true!

In truth it was a good exercise to see whether the silicon fluid had degraded in the wheel cylinders (it should not have done and it looks like it didnt). Since 2007 I have done 25,000 miles in this car including a lot of Alpine driving with a rapid descent of the Stelvio pass when the car lost its brakes right at the last hairpin (they recovered after a 15 minute rest....).