brake fluid

Post by **steve4063** » Fri May 11, 2007 8:40 pm

i presume i can use DOT 3 brake fluid

i've completely emptied the whole system and re-newed all copper pipes.

order of bleeding is paseenger rear, drivers rear, passenger front, drivers front.

is this correct???

Post by **bigginger** » Fri May 11, 2007 8:51 pm

Right order, yup, but dot 3? Surely 4?

Post by **steve4063** » Fri May 11, 2007 10:28 pm

really i was told 3 is that not right?????????

he said it should be 2 but as they don't make it use 3

Post by **bigginger** » Fri May 11, 2007 10:52 pm

Somebody will know for sure - I'm going on memory, and would hate to be wrong over something like brakes

Post by **RogerRust** » Sat May 12, 2007 8:24 am

I used DOT5 silicone brake fluid.

On the subject of bleeding brakes here is a repeat of a previous post;

RogerRust wrote:I think the problem lies in the rear cylinder design and arragement.

I know this has been discussed several times but here are some pic to illustrate the problem

This is the path the fluid takes when bleeding the rear cylinder.

There is only a small hole in the cylinder;

My solution is to fill the cylinder with brake fluid just prior to bleeding like this;

I hope thats not teaching my grandma to suck eggs, but I thought it might be usefull

Post by **DaveC** » Sat May 12, 2007 8:36 am

I was recommended DOT 4 by the garage, this is suitable (according to the blurb on the side) where DOT 3 or DOT 4 is specified. (It also says it is 'synthetic').

I had a look in my manuals and it just says 'Lockheed Super Heavy Brake Fluid SAE70 R3'. (Do not use mineral type oil).

Hope this helps
Dave

Post by **Welung666** » Sat May 12, 2007 8:40 am

Any synthetic varieties of the DOT3 and DOT4 can me mixed and used without problem. Only use the mineral based DOT5 if you have an entire new braking system, IE pipes and new seals all round as it will very quickly rot out the old rubber seals.

Post by **bmcecosse** » Sat May 12, 2007 8:52 am

Dot 3 is fine. Using silicone fluid is all very well - but only if everything is new in the system. Copper is NOT a good idea for brake pipes - Kunifer is what you need, and may very well have.

Post by **steve4063** » Sat May 12, 2007 7:32 pm

finally got the car running and bled the brakes took a long time but seem to have gopt there.

the pedal travells about 1/2 the way down until it goes stiff.

also if u then keep the pressure on it will go to the floor.

is this right or is there still air in the system?

Post by **gairlochrosie** » Sat May 12, 2007 7:35 pm

should not go to the floor

still air in there!!!.....did you prime the cylinders? Minor brake pedal should be hard!!

Post by **steve4063** » Sat May 12, 2007 7:36 pm

just used the nipples as i haven't touched the cylinders only re-newed the copped pipes, so i presumed that they wouldn't of been affected

i will say tho the old fluid was nearly black so it was nice to see clear coming out

Post by **gairlochrosie** » Sat May 12, 2007 7:42 pm

You still have a lot of air in the system...sometimes it can take a while to get them right.....and other times you can get it on the first attempt.....afraid, its back down and do it again...if the old fluid was black....you would be aswell to clean out the cylinders too....that way it will let you see the condition of the cylinders....if they are scored, get new ones...if not, maybe get away with a service kit for them...but you really need to prime them prior to the bleeding process

Post by **steve4063** » Sat May 12, 2007 7:49 pm

whats the best way to do it then please and thanks

Post by **gairlochrosie** » Sat May 12, 2007 7:51 pm

Also, when fitting the new pipes, make sure they are nice and snug connections or they will draw air into your system.

Post by **gairlochrosie** » Sat May 12, 2007 8:01 pm

You must go through brake systems in a systematic manner....otherwise, you're on a wing and a prayer.

I don't know what you have done up till now....but my advice is go back to the begining and start again. Only this time, in a systematic manner.

Post by **steve4063** » Sat May 12, 2007 8:06 pm

i done rear passenger, rear driver, front pass, front driver keepin fluid topped up i used 3/4 of a bottle

Post by **gairlochrosie** » Sat May 12, 2007 8:09 pm

Yes that is the right system to use....but you said, the fluid was black...firstly: what condition was the brakes before you started to strip the pipes off?? did they work? had a good firm pedal? or no brakes?

Post by **steve4063** » Sat May 12, 2007 8:12 pm

i think they were good i've took them all apart and all the shoes look fairly new and loads of tread no visible signs of fluid inside around cylinders etc it looked pretty clean.

i never actually drove the car as it is a complete restoration so not sure what they were like

i'll try giving it another go