New Brake Master - says no silicon!

[RogerH]

 

 

but learning just now that it was developed by the US military for long-term storage of their vehicles is a real bonus.

 

DOT5 fluid going in today!

 

Gavin

Hi Gavin,

I feel like coming all the way to NZ and giving you a good slapping

 

keep up the good work.

 

Roger

[KiwiTR6]

Hi Gavin,

I feel like coming all the way to NZ and giving you a good slapping

 

keep up the good work.

 

Roger

 

Hi Roger,

 

I figure that if it's good enough for Ed to use, then it's more than good enough for me!

 

That said, there is a bed here any time you're over this side of the world

 

Gavin

Edited September 16, 2018 by KiwiTR6

[Spit_2.5PI]

I've been using DOT-5 for 9 years now and found it perfectly good. Especially when I had to change a pipe, got it wrong, and found fluid on the deck around the MC.

 

After a comment about DOT-5 being seal compatible (and that's been my opinion because it is, I assume, based on silicone oil which is compatible with rubber ... and most things) I looked up some compatibility charts and found to my surprise that there is one seal material it *ISN'T* compatible with. Can't remember at the moment - is it silicon rubber? But it occurred to me that some suppliers may have changed the seal materials - possibly to save money. If you're worried, perhaps because of dire notices about only DOT-4, then do a test. Put the seal half in DOT-5 for a few weeks and see if there is any swelling evident, indicating deterioration of the material. A wire hook will hold the seal and keep one part in air, so you get that interface where any swelling becomes obvious.

 

Cheers, Richard

[RogerH]

Hi Richard,

now you are finding the problems !!!

 

The fluid should make the seal swell slightly in order to keep it(the seal) working correctly.

 

Silicone fluid (DOT5) has a good number of additives and one is for swelling.

The EG fluid (DOT4) also has additives for swelling and many other things. Are the swelling additives the same in both cases - who knows - nobody is telling.

 

However what happens if you put a seal contaminated with one fluid into the other fluid. Will it swell more or go soggy - nobody is telling.

 

Ensure your system is clean and fitted with new seals if you ever change in either direction

 

Roger

[DaveN]

Hi Richard,

now you are finding the problems !!!

 

The fluid should make the seal swell slightly in order to keep it(the seal) working correctly.

 

Silicone fluid (DOT5) has a good number of additives and one is for swelling.

The EG fluid (DOT4) also has additives for swelling and many other things. Are the swelling additives the same in both cases - who knows - nobody is telling.

 

However what happens if you put a seal contaminated with one fluid into the other fluid. Will it swell more or go soggy - nobody is telling.

 

Ensure your system is clean and fitted with new seals if you ever change in either direction

 

Roger

I tried that Roger along with heating the fluid..... it made absolutely no difference at all. In fact the little pot is still in my workshop with the old brake seals (DOT4) soaking in DOT 5 ....they have not dissolved, gone hard or even changed colour. They have been there now getting on for two years. There is a dead wasp in the pot if that counts? Edited September 16, 2018 by DaveN

[Waldi]

I once filled an XK140 with SBF.

Car had a fresh body off 1 year before and was initially driven with DOT4.

The SBF can said it was compatible with DOT4.

Before adding the SBF, I blew the system empty with compressed air, as much as possible, but it was not enough to remove all DOT4.

When I filled her up with purple colored SBF (forgot which make), and started with bleeding the system, i noticed the 2 fluids did not mix. So kept on bleeding uuntil no more DOT 4 came out.

Thought it would be ok, since the bottle said so.

It was not.

During one drive short after this change, my front(drum) brake seized. When I relieved rhe bleed nipple on the cilinder, it was released and the brakes worked ok.

We continued rhe tour, but after 1 km or so it seized again.

So we released the cilinder on rge wheel again and drove home at slow pace.

At home I dismantled the entire brake system and found the small diameter expansion hole in the MC that allows fluid to return to the reservoir when the brakes get hot was plugged.

So thoroughly cleaned all components, replaced ALL the rubber components, and filled up with DOT4.

It was ok after that.

 

 

Will I use DOT5 (SBF) again?

Probably, but only on a completely clean (and new built) system.

I have, triggered by this conversation, asked Moss and Past Parts for their recommendation/opinion, since they supplied most of the parts to me.

Will keep you informed of their feedback.

Regards,

Waldi

[stuart]

I once filled an XK140 with SBF.

Car had a fresh body off 1 year before and was initially driven with DOT4.

The SBF can said it was compatible with DOT4.

Before adding the SBF, I blew the system empty with compressed air, as much as possible, but it was not enough to remove all DOT4.

When I filled her up with purple colored SBF (forgot which make), and started with bleeding the system, i noticed the 2 fluids did not mix. So kept on bleeding uuntil no more DOT 4 came out.

Thought it would be ok, since the bottle said so.

It was not.

During one drive short after this change, my front(drum) brake seized. When I relieved rhe bleed nipple on the cilinder, it was released and the brakes worked ok.

We continued rhe tour, but after 1 km or so it seized again.

So we released the cilinder on rge wheel again and drove home at slow pace.

At home I dismantled the entire brake system and found the small diameter expansion hole in the MC that allows fluid to return to the reservoir when the brakes get hot was plugged.

So thoroughly cleaned all components, replaced ALL the rubber components, and filled up with DOT4.

It was ok after that.

 

 

Will I use DOT5 (SBF) again?

Probably, but only on a completely clean (and new built) system.

I have, triggered by this conversation, asked Moss and Past Parts for their recommendation/opinion, since they supplied most of the parts to me.

Will keep you informed of their feedback.

Regards,

Waldi

Your experience is the same as several I have had over the years, hence why I wont use it or recommend it

Another thing you might like to remember is when you spill silicon on your paintwork yes it wont attack it but god help you if you ever want to paint anywhere near it again.

Stuart.

[Mike C]

I'm sticking to DOT 4 unless the improved glycol fluid DOT 5.1 (???) becomes more widely available.

 

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=14&cad=rja&uact=8&ved=2ahUKEwjat8jStr_dAhWMfLwKHY9oBXQQFjANegQIBBAC&url=http%3A%2F%2Fwww.apecbraking.co.uk%2FApec%2Fmedia%2Fproduct-bulletins%2FBrake-Fluid-FAQs.pdf&usg=AOvVaw0BOIyAlWfxPlgx_BfAN2tA

[stuart]

I'm sticking to DOT 4 unless the improved glycol fluid DOT 5.1 (???) becomes more widely available.

 

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=14&cad=rja&uact=8&ved=2ahUKEwjat8jStr_dAhWMfLwKHY9oBXQQFjANegQIBBAC&url=http%3A%2F%2Fwww.apecbraking.co.uk%2FApec%2Fmedia%2Fproduct-bulletins%2FBrake-Fluid-FAQs.pdf&usg=AOvVaw0BOIyAlWfxPlgx_BfAN2tA

DOT5.1 is very good but does need to be changed more often than standard DOT4 As to availability your end try this https://www.supercheapauto.com.au/p/sca-brake-fluid---dot-5.1-500ml/341717.html?cgid=SCA01070505#segment=1&page=1

Stuart.

[Mike C]

Thanks Stuart. There's a Supercheap close by and a change every two years would be acceptable.

[rogerguzzi]

Hello Roger

where can you get some of this addative????

 

has a good number of additives and one is for swelling.

 

Roger

[RogerH]

 

You naughty boy

 

Roger

[Tim D.]

Did the dot4 to dot5 switch in my TR6 when I bought it. Ran one in the letting the other run out. Because they don't mix and are different colours it is easy to see when it is complete. Mind I am not saying I got ALL the dot4 out. Anyhow that was a number of years ago and all is fine.

Tim

[Waldi]

I have, triggered by this conversation, asked Moss and Past Parts for their recommendation/opinion, since they supplied most of the parts to me.

Will keep you informed of their feedback.

Regards,

Waldi

I contacted Moss and Part Parts, here are their responses (not literally):

 

Moss:

"Yes, SBF is acceptable for use with our components". I add this off course only applies for parts supplied by Moss.

 

Past Parts:

"SBF is generally NOT recommended because of the issues it can give, some clients are happy with it, others not.

Advantages are: It is not-hygroscopic (hence less corrosive) and it does not destroy paint in case of leakage.

Disadvantages reported in the past are: compressability (softer pedal) and lubricibility.

Also, DOT 5 (SBF) was not listed with the acceptable brake fluids by component suppliers.

Lockheed did not recommend SBF in the past for this reason.

But if you want, you can use SBF on our components" in a clean system.

 

 

Since my system is completely rebuilt and no fluid is in, I will use SBF.

I would not use SBF if the system was previously filled with DOT 3 or 4. Just my opinion.

 

Regards,

Waldi

Edited September 18, 2018 by Waldi

[Waldi]

Sorry, I'm not able to modify the above post just 2 mins after posting:

The recommendation from Past Parts includes... "But if you want, you can use SBF on our components in a clean system"

 

Waldi

[RogerH]

 

Advantages are: It is not-hygroscopic (hence less corrosive) and it does not destroy paint in case of leakage.

 

 

Hi Waldi,

thanks for that posting.

But it does go to show how the lack of information or wrong information gets around.

 

The DOT3 or 4 being hygroscopic actually helps it being less corrosive as any 'water' is enveloped in the fluid. This fluid s full of inhibitors etc.

The DOT5 allows the 'water' to stay as puddles of water and thus it can attack the inner lining of pipes and castings,

 

DOT 3 or 4 must be changed regularly - every 2 or 3 years - to maintain its anti-corrosive properties.

 

Roger

[Waldi]

Thanks Roger.

Water especially ingresses at the rear wheel cylinders on our TRs due to the absence of a proper seal; the dust cap is not completely tight, so moisture will be attracted here. Poor design, compared to the more universal design like Opel (GM) had in those years

I used DOT3 and later DOT 4 since I was 15 years old and started doing maintenance on family cars like Opel Kadett.

I replaced a bit on each wheel cylinder/caliper yearly until clear liquid came out.

Labor rate was nil:), and it gave me satisfaction (yes, I had it in me then) knowing the dirty fluid was removed.

I did experience very little issues over the years.

Cheers,

Waldi

[Mike C]

Good point Roger,

 

"The DOT5 allows the 'water' to stay as puddles of water and thus it can attack the inner lining of pipes and castings," - especially the machined steel surface at the bottom of master cylinders.

[stuart]

Good point Roger,

 

"The DOT5 allows the 'water' to stay as puddles of water and thus it can attack the inner lining of pipes and castings," - especially the machined steel surface at the bottom of master cylinders.

Another reason I dont use it.

Stuart.

[KiwiTR6]

Well, I managed to get Ruby back on the road today after the bank manager kindly helped me do a final bleed of the braking system.  Just to remind anyone who may have been following my (very slow) progress, I've re-kitted the front calipers and fitted Mintex 1144 pads along with TRD grooved and drilled discs.  I've left out the anti-sqeal shims (for good reason in my view) and instead coated the backs of the pads with anti-squeal compound.

At the rear I've replaced the wheel cylinders with the slightly larger Morgan items, repaired (welded) the backing plates where the handbrake lever pivots sit (thanks for the how-to Stuart), and replaced all of the rubber hoses with Goodridge braided hoses.  In addition, I've installed a 12V servo pump from a wrecked Audi to increase vacuum to around 12".  And of course, to top it all off -  the system (after cleaning everything first) is now filled with DOT5 brake fluid.

I headed off quietly to a nearby side road to bed in the pads as per the supplier's instructions, but came to an embarrasing standstill at the gas station down the road when the fuel pump refused to run after I'd filled up with petrol.  It took me a wee while to figure out what had happened, but it was soon enough to stop the bank manager making a wasted trip  (she was quite pleased to be relieved of towing duties as you can imagine).  It seems the clever little chinese anti-theft device I'd installed in the fuel pump circuit under the dash had decided to give up the ghost, but thankfully it's equipped with a bypass switch so the problem was fairly quickly rectified and I was back on the road again.  I might also mention that this was the first test for my new home-made exhaust system and heavily modified rear tube shock conversion.

After performing the specified sequence of heavy braking and cooling periods, I headed off to my local test loop and tackled it at a fairly brisk pace as the engine just seemed to want to get on with it.

What a difference in so many respects!!!

The brakes are magnificent, as good as any of our modern day drives and light-years ahead of the original system.  I can feel the front pads biting into the discs rather than just rubbing against them, the retardation is immediate and the car pulls up quickly giving the driver complete confidence, just as I'd hoped.  I can feel no softness in the pedal from the use of the DOT5 fluid (although I will give the system another bleed after a little more use), but this may have been offset by the change to braided hoses. 

I'm over the moon with the result and was on a high when I arrived back home as not only were the brakes a huge success, but the new exhaust allows the engine to pull and rev much stronger and freer than it ever did before (and without being annoyingly loud), plus the ride and handling is an absolute joy!

It was a bit of a drawn out process making all of these changes in one hit, but the effort has been well and truly rewarded .....

 

 

Gavin

 

 

 

[RogerH]

Hi Gavin,

              good to hear all is well.  I'll be over for a cuppa and drive in the car.

 

Roger

[astontr6]

On ‎9‎/‎15‎/‎2018 at 1:44 PM, boxofbits said:

Yes its a convoluted argument with no real conclusion.

 

I do find it hard that though that Moss Europe, being possibly the largest single supplier of Classic Car Components are prepared to endorse DOT 5 on their website. Surely they would be opening themselves up to litigation if incorrectly advising owners to use it.

 

https://www.moss-europe.co.uk/dynolite-silicone-brake-fluid-dot-5-1-litre-ggl862110.html

Kevin.

Hi all,

Unfortunately how many people on this forum have been let down by Moss's technical expertise and quality? I have many times, too many times to remember!

Bruce.

 

 

 

[KiwiTR6]

An update on my DOT5 conversion.

Took the car for a WOF (warrant of fitness) today and the tester commented that the brakes performed better than those of any other classic car he's tested, so a successful outcome there.

However, there was an issue between original completion of the conversion and the test. Last weekend I thought I'd do a final bleed to remove any residual air bubbles.  After a couple of bursts on the back brake my lovely assistant commented that she had no pedal - uh,oh.  The job ceased at that point whilst I tried to figure out what had actually happened.  Eventually, I concluded that the MC piston must have jammed in the bore and not returned.  I suspected that one of the seals had swollen as the MC seals were the only ones that I hadn't replaced, so had been exposed to DOT for 7000km and then the recently added DOT5.  

I removed and stripped the MC (again - now lost count).  The front cup looked fine but the rear circuit seal ring looked a bit floppy in the groove.  I ordered a TRW kit from the local TR Register and when this arrived I could see that the rear ring was indeed enlarged.  I also noticed that there were no identifying marks on the seals and the tilt valve was quite different.

Needless to say, the whole system is now fitted with  new seals that have only ever been exposed to DOT5 fluid.  Hopefull that is the end of the matter.

An important lesson learnt - changing to DOT5 is not simply a case of drain, flush and fill!

Gavin

[EXTR6]

When I buy my ca r- sooner rather than later, I hope - is there anyway of visually establishing, at the reservoir, which break fluid is in the system?

Are there also issues affecting the choice of clutch fluid?

[EXTR6]

oops!

Thanks and regards

1 minute ago, EXTR6 said:

When I buy my ca r- sooner rather than later, I hope - is there anyway of visually establishing, at the reservoir, which break fluid is in the system?

Are there also issues affecting the choice of clutch fluid?

Brendan