advisory on MOT mk1

[shepped0]

Hi All

My mark one went through its mot today with flying colours except examiner said that the brake fluid reservoir needs topping up.
He didn't want to put fluid in it in case he was mixing with the wrong stuff.
I am keen to top this up but again don't wanna put just anything in.
Any advice what should be put in it...I have no idea what is in it, i.e grade etc and this would have been changed by someone else not me.It may be a case to do a full flush and change as it has been in there at least since I have owned it.
Any advise very welcome.

Kind Regards

[FredTransit]

Might be best to change it. If you have the servo under the bonnet, use Dot4

[Brains_transit]

Brake fluid needs changed after a certain time

[shepped0]

I think a complete change may be a good idea its been a long time. I cant think where the servo is ... I will take a look tonight to see if its under the bonnet then get myself some Dot 4

[DougT]

Don't be tempted with the DOT5 as, while it lasts longer, it also rots the seals, especially old ones.

Newer is not always better.

Doug

[Neil]

I think a complete change may be a good idea its been a long time. I cant think where the servo is ... I will take a look tonight to see if its under the bonnet then get myself some Dot 4

is yours early not all had a servo

[FredTransit]

Dave's is a 69

[baconsdozen]

Interesting,I heard somewhere that the later (Dot5) fluid is liable to damage older seals but can't remember where. Does anyone else have any info on this?.

[Mr RVM]

Interesting,I heard somewhere that the later (Dot5) fluid is liable to damage older seals but can't remember where. Does anyone else have any info on this?.

Unless you are going to fully clean out the whole system and remove all traces of DOT4 you Should NOT use DOT5 fluid as they are NOT compatible (tho some may dispute this) but you CAN do a full fluid change using DOT5.1 as this is an improvement over and compatible with DOT4

Oh and by the way...most manufacturers recommend changing the brake fluid every 2 yrs (how many people take any notice of that )

[DougT]

Interesting article from Opie Oils

https://www.opieoils.co.uk/pdfs/tech-ar ... lained.pdf

In summary to quote the article:

Quote
There are two main types of brake fluids:
* DOT 3, DOT 4, Super DOT4* and DOT 5.1 which are based on poly glycol
compounds.
* DOT 5, which are based on Silicone.
Note the two types of fluid are not compatible and must not be mixed in
a braking system.

BOILING POINT:
DOT 3 - 205°C (dry) / 140°C (wet)
DOT 4 - 230°C (dry) / 155°C (wet)
DOT 5 (silicone) - 260°C (dry) / 185°C (wet)
DOT 5.1 (PAG) - 260°C (dry) / 185°C (wet)
Super Dot4 * - 300°C (dry) / 195°C (wet)

End Quote

I had always thought DOT5.1 was another silicone fluid like DOT5 so thanks to MrRVM. And apparently it is because the water is not fully absorbed and "pools" with DOT5 that it rots the seals.

Doug

[shepped0]

Blimey Guys what an in depth analysis.
I think in my position it would be wise to change the fluid completely and just use Dot 4.
My father would have last changed this and as he is no longer around it could well be the first ever brake fluid ever produced !
Do you know I am struggling to find a servo ...so maybe I don't have one could this be right ?
As Fred has stated it is a 69 (pedals through the floor model).
I was also advised to grease up the King Pins, albeit not worn, examiner said was advisable. I have a grease gun for this and believe there is a small nipple where the gun attaches.
Will endeavour to do all above and again thank you all for your help

Regards

Dave

[Neil]

early models a servo was an option if theres not one in the usual place above the steering column the option was on the passenger side inner wing if theres nothing but a resavoir then you don't have one

[Ellwood]

another tip - park the van on an incline, with rear end uphill. bleed the brakes starting at the nearest brake to the servo, and furthest last.

its not a bad idea to change the brake hoses while you are on - they can clog up after even 15 years, so they reckon. and definitely after 40.

as for the servo - mine has pedal through floor, and has 2 servos. one is hidden under the battery , and a bugger to get at - hence my 6x4 inch hole in the battery holder plate

dont forget to replace the cap when youre finished ( like i did - i was lucky to find it a mile down the road, undamaged)