A610 brakes

If you read that above it actually states that 5.1 has half the viscosity of 4 ?? So how does that tally with the ABS compression factor ?

http://www.motul-oil.co.uk/pdfs/brake-f ... 8GB%29.pdf

Like a dog with a bone

I think Rob's ABS is one of the few that actually works ??

I'm bored and on roast dinner duty ....

Interestingly it would seem that not purging the system completely is where it all goes wrong .Any mixture with dot 3/4 is where the corrosion factor comes in when using 5 .Stripdown and purge is the only sure way as I suspect most cars have had the wrong type in at some point ( whichever that is )
If the ABS has been designed for dot 5 then the compression rates will have been accounted for .

[stephendell]

I understand that it was simply a common labelling mistake at the time. 'Real' Dot 5 was not widely available in Europe in the late 1980s early 1990s and anything labelled Dot 5 meant Dot 5.1. This was common to a few manufacturers at the time. Dot 5.1 is actually a development of Dot 4 specifically for ABS and as far as I am aware that was what was intended. The manufacturer did not factory fill with silicone.

[stephendell]

Also the 610 ABS system is basically the same as the GTA and that was glycol filled as well.

Oh well ...I stand corrected ...sort of ish

I didn't realise everyone had the yellow label from the factory. That seems incredibly dodgy. Anyway so long as it was indeed designed for DOT 3/4/5.1 and mine isn't been modified, I should be ok. I used the same ATE super blue which is officially DOT 4 but exceeds the spec. I'll report back on whether my ABS still works once I sort out the fluid leak and finally get an MOT.

Lee are you sure the threads are tapered? The hose ends looked square to my eyes when I had them off, not that I was looking very hard. I'd like to confirm before I take it all apart again. Andrew suggested I try PTFE tape if it is indeed tapered, and if not I may be missing some sort of crush washer.

Finally has anyone used upgraded hoses? It might be easier to change the whole hose than to take the calipers back off, especially since one of mine is rounded at the end anyway.

[stephendell]

That Motul fluid you linked too looks OK as well.

I had a cheapo (car plan or similar) 5.1 but kept losing the clutch at Bruntingthorpe after high speed runs so switched to the super blue and that seemed better. Pretty sure my ABS wasn't working anyway so nothing to lose!

Another bit of trivia, as I understand the reason super blue is Dot 4 not 5.1 is because the 5.1 standard does not allow any coloured dyes.

The dye is useful as it shows when all the old fluid has been bled out. They do a yellow version too so you can alternate.

[stephendell]

Andy swears by Castrol SRF in a race car but be prepared to dig deep in your pockets.

Normally tapered thread but TBH I can't say for certain .

Motul sbf 600 is also good

Generally though I think the best option is to change it every year as part of routine service .If you are tracking it then more so .

[mettersl]

Anyone know what the service manual says? Mine has the dot 5 sticker and I always assumed it was right, if odd when thinking about abs. Dot 5 is similar to aircraft silicon fluid and is designed to prevent water take up. Std brake fluid absorbs water from the air....hence the need for regular changes.
This one will run....
I'm sure the abs issues on 610s are electrical. On mine the pump and valves work,but the system seems to be unable to detect wheels moving at different speeds. I have tried running mine with the rear wheels off the ground, this should give an abs error ( as should rolling road tests) as the car is supposed to detect any sped differences above 5? Mph but doesn't.
It's one of the oddities, early press 610s and lhd ones seem to have working abs....suggesting a generic rhd system fault.
Lee

M.R.297 Manual says DOT 5 .