brake fluid flush

[Kevgem]

hi everyone, i got a brake fluid checking tool the other day only a cheap pen type thing, had a look on YouTube for reviews and was surprised how accurate it was for a cheap bit of kit. to cut a long story short, if you have a look at my other posts i am not known for cutting story's short lol. anyway it lit up like a Christmas tree indicating i must change my brake fluid strait away. i don't know what fluid is in there already i.e (glycol base or fully synthetic), i know its dot 4  and seen some dot 5.1 advertised and wondered if this would be a good upgrade? 

cheers kev! 

[chimaera]

DOT 4 is fine. Brake fluid is supposed to be changed every 2 years anyway.

[Kevgem]

what about it being glycol or synthetic ? 

i don't know which one of them is already in there ?

which one is it supposed to have ?

cheers kev 

[StevesTruck]

It will be synthetic, I don't think you can buy glycol based any more, well maybe through a classic car parts supplier.

 

Dot 4 is fine. You only need 5.1 if you're going to be getting your brakes really hot, basically sustained track use or driving for deliveroo 😜. 5.1 can make the pedal heavy on some cars. 

Edited 9 October, 2022 by StevesTruck

[Kevgem]

thanks for the help lads!

[Kevgem]

dose anyone know the capacity for the brake fluid?

so i know how much to buy?

(mk2 4x4 estate)

cheers kev!

[StevesTruck]

A litre bottle should be plenty. I normally have a second one in hand in case something properly stupid happens, but the reality is I've changed the fluid on a polo, my bike (that got messy because something properly stupid happened) and my van and have only used 1.5 litre. 

[Kevgem]

right thank you!  I have ordered 2L of the proper skoda brake fluid so will have enough to do the flush and have some over just in case 

cheers kev!

[DEL80Y]

Just to be a pain 

Are you also flushing the ABS pump 

This doesnt get flushed with  a standard flush    |

You need diagnostic equipment to get the pump to bleed itself

I was amazed how dirty the fluid was coming out after doing the correct procedure
 

 

[bigjohn]

On 11/10/2022 at 19:02, DEL80Y said:

I was amazed how dirty the fluid was coming out after doing the correct procedure

 

Indeed - In the past I've seen all sort of horrors re brake fluid especially when repairing restoring cars the stuff I've drained off has been unbelievable and it's hard to imagine some of these were still being driven just before being stripped.

 

The worst was a 1990 Passat with a regulator valve on the rear axle that was trapping brake fluid no matter how you bled the system - in the end all pipes/valves/cylinders were all replaced and bleeding had to include different valve positions. Some of the original fluid came out looking like chocolate milk!! 

 

A close second was a 1986 Volvo 740 Estate(my Dad's!)  that looked like it had a black brake reservoir (it didn't but it rather changed colour as you bled the system!). It was a right swine to properly bleed as it had fluid trapped in a strange cross circuit switch/sensor which sensed a circuit fail. In turn that switch/sensor was sticking as the internal ball assembly separating the system  was starting to rust internally! Even when you changed the switch it was hard to get the air out of that bit. There wasn't an electronic procedure to help back then! Saying that it was an impressive dual circuit setup - each front brake caliper had a piston/bleed valve on each circuit and considering I found out the brake fluid was over a decade old at the time all the pipes & nipples came undone. 

 

Re the original post though it's not always enough just to test what's in the brake master cylinder reservoir as this fluid may have been topped up with fresh after a brake or clutch job but that won't have replaced it elsewhere in the system.

 

 

 

 

Edited 13 October, 2022 by bigjohn

[Kevgem]

would any diagnostic tool be able to do that or has it got to be a specific type?

is it a job that would have to be done by Skoda main dealer or would any decent garage be able to do it?

cheers kev!

[chimaera]

14 hours ago, Kevgem said:

would any diagnostic tool be able to do that or has it got to be a specific type?

is it a job that would have to be done by Skoda main dealer or would any decent garage be able to do it?

cheers kev!

As long as the diagnostic tool fully supports VAG diagnostic protocols, it should be able to do the job.

[Kevgem]

ok thank you!

[DEL80Y]

For home use there is  nothing better than Autel AP200  available at Amazon for £58