Occasionally sticky front caliper...rebuild or a new pair?

[Laird Scooby]

Originally Posted by Prufrock

I would always use a contemporary product if available, obviously there are exceptions. Mind you, you might have bought that tub of cooper grease 20 years ago and still have half left today !

J.

There are definitely some exceptions to contemporary products Jon - OAT antifreeze for one general thing, there's a whole thread on various different oils on here, ATF is another one - all can do untold damage if the wrong (newer usually) product is used.

Copper grease is always useful though!

[Prufrock]

That's contemporary with the age of the car.

J.

[TonyS9]

The Volvo pinset comes with silicone grease which I used along with the new rubber gaters etc. However my lower pins still rusted and seized (lightly) a few years later.

I do do low mileage, and when I do I can drive pretty hard.

[AllHailKingVolvo]

Interesting stuff, thanks guys!

I’ve used Copaslip for years on kart piston faces, I’ve got a tub of it that’s all left than me-my old man was in the motor trade for 40+years and could never throw out stuff like that when he retired!

I have a slight judder under braking so I’ll probably do discs and pads along with a caliper clean and refresh, plus cleaning up and greasing the pins.

I’d like to bleed the system and freshen up the fluid as it’s old and murky. Do any of you chaps use Dot 4.1? I know it’s compatible with most Dot 4 systems and is regarded in endurance kart racing as a secret weapon for the summer due to the higher boiling point.

[Laird Scooby]

Chances are it's the sticky slides causing your judder as well Phil but if you want to do discs and pads, be my guest!

As for the DOT 4.1 fluid, you probably won't gain any benefit from it unless you drive your car like a go-kart on the track when you're on the road.

If you don't already have one, invest in a Gunsons Ezi-Bleed to change the fluid. It took me about 10 minutes to do mine using one of those, excluding the time to get the car in the air with the wheels off.
It also worked better with 30-40psi than the "recommended" 20psi for me.

[Jebus]

Originally Posted by Laird Scooby

Out of curiosity, what do the green Books say for the 7xx series?

For TP 30863/2 brakes service guide it states to use special grease, which gives part no for synthetic molybdenum grease, this is for the 740

A slightly later guide for 700/900 series on "jumbo" brakes, it states a silicon grease.

the books are very handy, i went for the 700 and 900 discs with them all sime the OTP discs are not the most well thought out things in some ways.

I use what I use, and other what they do if it works, it works!

Lubrication and where to use what is probably one of the most argued about topics on car maintenance

Oh and brake judder, the greenbooks have whole sections on that as well

[TonyS9]

Originally Posted by AllHailKingVolvo

I’d like to bleed the system and freshen up the fluid as it’s old and murky. Do any of you chaps use Dot 4.1? I know it’s compatible with most Dot 4 systems and is regarded in endurance kart racing as a secret weapon for the summer due to the higher boiling point.

Do you mean 5.1? I think I need this
-edit to add - actually dot 4 racing fluid is much higher spec than 5.1 eg Motu RBF660 has a 325C dry boiling point, compared with 260C for dot 5.1

[AllHailKingVolvo]

Originally Posted by TonyS9

Do you mean 5.1? I think I need this
-edit to add - actually dot 4 racing fluid is much higher spec than 5.1 eg Motu RBF660 has a 325C dry boiling point, compared with 260C for dot 5.1

Yes 5.1!! Sorry my mistake...I have been out of the Karting scene for a couple of years hence the “senior moment” about the fluid spec!

Very interesting about the Dot 4 racing fluid. I’ll do some more research and see what i can find out!

Cleaning and lubricating the slide pins will be my first port of call. I’ve just changed the discs and pads on my daily (2003 Merc C220CDI) so my brain is firmly in brake fettling mode.

[TonyS9]

I'm currently putting Merc A class brakes on my Volvo 360 for track days