Dot 4 vs Dot4 LV Brake fluid on C5 and Xantia

[yoseff]

I need soon to change Brake Fluid on my C5 and also in Xantia (Before laughing at me , please read it till the end )
Been looking for alternatives and i found something called Dot 4 Low Viscosity and also Dot4 Class 6 (unsure if it's the same thing) , that is supposed to be used on cars with ABS and ESP.

Could C5 (X7) benefit from it? Or a ATE TYP 200 would be a better choice?

Got myself one of those pumps to change brake fluid with pressure and i think that will be ok for both C5 and Xantia (Something like this: https://pt.aliexpress.com/item/1005006444069240.html)

Anyone have experience around here with these things? Would like to change the fluid as soon as i could have time for do it.

For the Activa , Dot 4 is just for the clutch , so i think i will not have any benefit from the Low viscosity thing.
What's your thoughts on it?

[citroenguy]

Never used anything other than normal Dot4 fluid at work or else.
Unless it especially calls for LV brake fluid i wouldn't bother. Service box just says "dot4" C5x7.

But i've only been working with Citroën and Kia, maby it is a VAG/Mercedes/Bmw thing?
The Germans like to "do their own thing", not just the French XD

[yoseff]

I think i will go with the ATE TYP 200 then. It seems to be just a better DOT 4 with higher boiling points.
Any advice on using the tool other than not putting too much pressure on it?
Need to find the details on how to bleed the clutch. The mechanism to do it seems bit distinct from the brakes...

[RichardW]

The Activa clutch may not be bleedable - on right hand drive cars they were a sealed unit.

[xantia_v6]

The Activa clutch may not be bleedable - on right hand drive cars they were a sealed unit.

That was also true for LHD cars before 1999, but late LHD cars got a clutch reservoir next to the LHM tank and I think a screw on the clutch slave cylinder to allow bleeding.

[yoseff]

The Activa clutch may not be bleedable - on right hand drive cars they were a sealed unit.

That was also true for LHD cars before 1999, but late LHD cars got a clutch reservoir next to the LHM tank and I think a screw on the clutch slave cylinder to allow bleeding.

Yes, mine has a reservoir. It's from 2000
Need to check the fluid, but it wouldn't be a surprise if it was 24 years old

[citroenguy]

Those brake blöeeders work, but i'm not sure i'd use it on the xantia clutch. Maby with just 1 bar.
I usually use the air-powered vacuum bleeders, on my friends Xantia HDI 110 i did a few partial changes by emptying the reservoir an filling with new fluid every time he came by.

[PaulC5]

I have been using a Mityvac pump for many years to bleed brakes and clutches which sucks the fluid out of the bleed screws. https://www.amazon.co.uk/Mityvac-MITMV8 ... B000FUMWTM It can be slow and air can be sucked around the screw threads. The container is too small though so I made another one from an air tight food container with a screw on lid and 2 bleed screws fastened to the top with one pipe to the pump and the other to go on the brake bleed screw. I marked it up at 50 ml levels so I can see how much fluid is bled out.

I also have a Gunsons pressure bleeder but do not like using it since it puts pressure on the reservoir and if the bleeder is filled with fluid can spray out if the cap does not seal.

[Stickyfinger]

I always wondered about "Air being sucked past the bleed screw" after it has been cracked open Just how do you stop that happening ?

(I know it is of no concern with the Xantia brakes)

[xantia_v6]

I always wondered about "Air being sucked past the bleed screw" after it has been cracked open Just how do you stop that happening ?

(I know it is of no concern with the Xantia brakes)

Years ago you could buy bleed nipples with o-rings fitted between the thread and the point.

[Armidillo]

Otherwise I believe grease on the bleed nipple thread can help - although it would need to be brake-fluid compatible grease (eg. silicon).

[citroenguy]

I always wondered about "Air being sucked past the bleed screw" after it has been cracked open Just how do you stop that happening ?

(I know it is of no concern with the Xantia brakes)

As long as you have pressure or suction on the bleed nipple it is not an issue.

When you use the vacuum tool it can draw air from the threads and out into the tool, with visible bubbles. That is normal