Lotus Elan and Lotus Elan Plus 2 Forums

Hi all

Re this continuing argument about silicon fluid.

I'm no expert on these matters so it's personal experience only I'm afraid- the more informed out there will have to correct any errors but- as far as I'm aware for anything (solid or liquid) to absorb water doesn't it have to exhibit "annhydrous " qualities- this is my distant memory of chemistry lessons so a solid will have to have a lower moisture content than it's surroundings and attract water vapour (think biscuits). Where if another solid has a higher water content than its surroundings it will lose some of it (think bread).

OK a simple example and I know it involves a lot more factors than I've detailed.

In the case of "normal" brake fluid presumably its chemical composition means that it is a natural attractant for water (possibly irrespective of the surrounding water content of the atmosphere).

On the other hand (correct me) silicon fluid doesn't attract water because of its make up so why should a silicon hydraulic system "pull" in water if it's not combining with it.

I've used this stuff for over 20 odd years and have never found any "pools" of water in the systems when I've done a hose/seals change.

Car manufacturers "possibly" have a vested interest in systems that last longer than they'd like.

I also remember reading a long debate about this on an american car forum- one of the contibutors asked why the american military used silicon fluids in some of their hardware- and have done for many years if it was "suspect".

Just my thoughts.

John

Hi Guys,
Not much inclined to whack up the costs if I can avoid it, and as I said I don't have any issues the way it is. It's not broken and I am having no difficulties at all. 40 deg heat thro' the center of Le mans this summer at a crawl... So I don't see the need. Had I been experiencing problems then that would be different. But I am not.

Original question.... Is the std slave cyl the same for both the ford and the lotus boxes? If it is different and costly then I may consider the option. So... Can anyone tell me what the cost of the concentric device is?

Just another thing to factor into the will I wont I which as of now (still not spoken to Graham Boulton) is no more than 50-50....

I'm not too interested in the fluid thing..I know what you are saying but what's worked for me! I tend to believe what is written on the tin a bit..Normally works fine.. The clutch system has only had synth fluid in it, so I am continuing using it. Mrs B gets it for me and the cost is fine.

Thanks guys...


Alex..

Alex,

See my post earlier in this thread with photo.
I believe I reused the 4 speed slave cylinder and had no problems.

Regards,
Stuart.

I did notice that Stuart, but I was not sure if it was a Ford cyl or not. Hence the question. Are you telling me that is the case?

Good stuff if so. Its getting expensive this caper..

AB...

John, I think the theoretical objections to using DOT 5 fluids for "high performance braking" ie NOT military applications are

1/ Much higher compressibility.
You can report back to us if there is any discernable change in pedal feel.

2/ Much lower boiling point of any water in the system due to lack of miscibility. Ie if there are any water droplets, they will boil at the water boiling point because they do not dissolve into the brake fluid.
On this point, I guess house-keeping would manage some of the risk. I've always thought that Citroens with LHM brake fluid would suffer from the same problem but I've never heard of brake vapour lock being a significant problem with that Marque.

Regards
Gerry

Jas wrote:- Jim

From witch car does that slave come, a Saab 900?

It's an aftermarket performance part.

I just pulled the image off the web, but over here DBE has something similar in their catalog.

alexblack13 wrote:I did notice that Stuart, but I was not sure if it was a Ford cyl or not. Hence the question. Are you telling me that is the case?

Good stuff if so. Its getting expensive this caper..

AB...

Not sure what you mean by "Ford cylinder." The SC on my S2 is a Girling part. It is likely that it was used on Ford products as well.

Thanks Jim. Indeed that is what I meant. I know Ford don't make it and Girling does. Just asking if that was the std fitted Girling part on the 2000e box and if its the same fitted to the Lotus 5 speed box..


Tisall... Thanks

AB....

Hi Gerry

Pedal feel- can't say I've noticed much difference in this respect.

All I was saying about "attraction to water" is that conventional fluid seems to have an "innate" attraction to water. Since atmospheric pressure precludes water vapour being "forced" in thru the hose walls it presumably is being "pulled" in by the fluid.

I'd assume that since silicon fluid doesn't actually mix too well with water it doesn't therefore attract it.

I'd just repesat what I said earlier- manufacturers might possibly prefer a system that "requires" regular overhauls over one that means they can sell fewer of their goods- particularly where it's a major safety area.

Just my opinion as I said.

Regards

John

Update..... Decision made to go ahead. The gearbox is with Graham Boulton for specialist rebuild.

I have the propshaft.Clutch complete. and I think everything else needed. By the way... Graham said that the std spigot bush is fine and also so is the clutch fork (with slight mod). He said its an easy job in fact..


Where have I heard that before?

I am starting with the bonnet off to go to Option 1 for repair to the very slight dink I did during 'bonnet hurling practice'. I am then going to remove the sump for one of our members here. (Brian Give me a ring) Then I will gently take it apart doing some further slight mods as I go. Some rivnuts here n there for EG..

Big advantage = gearbox much lighter... Similar to my wallet.

Here we go again....

Al'

hi Alex,
I've picked up on your comment in Rivnuts.

I'm thinking of using them in a few places instead of self tappers or the screws that fit through plastic fixings. They look like a much better solution for fastening to the bodywork.

For fixing into fibreglass, do you use steel, ally or the rubberised rivnuts? Do you have any installation tips and do you find the fibreglass is ok with them in terms of cracks around the hole?

Any experience and advice lapped up gratefully as usual.

thanks
Mike

I've only used them in the fiberglass on a few locations and can't for the life of me remember exactly every location. I do remember fitting them into the door to hold the pull handles. They are great so far and holding quite firm. I had to do this OR strip the window frame ass'y back out as I forgot about fitting the handles 1st. Nightmare... I then fitted the riv-nuts (Alli) and Bob's your mums brother. I did not over tighten the fasteners though.

I am going to fit steel ones into the engine mounts and into the radiator fastener holes etc. Just here n there. Make life easier...

Plan A.. Don't have a plan B... Yet!

Cheers all

Al'

alexblack13 wrote: I am going to fit steel ones into the engine mounts and into the radiator fastener holes etc. Just here n there. Make life easier...

Alex,

I've used them here and there - engine mounts being one convenient place. You can see it at the show.

Will call you later.

I am going to fit steel ones into the engine mounts and into the radiator fastener holes etc. Just here n there. Make life easier...

Recently I sawed some nuts in half to make thin ones and put them on the rad mounting bolts so the bolt is rigidly fastened to the rad (having ascertained the correct position by leaving then slightly loose first try ). Makes life easier. The nuts (on the engine side) can then be easily undone with a ratchet socket.

Yes that woild work ok Bill. Why not just get some halfnuts?

I do like the rivnuts though...

Alex...