Brake fluid

[mp8200]

Hi

The brakes on my 65 chevy is not working properly anymore, and I can see the brake fluid reservoir is all empty so I have to refuel the system.

Which type of brake fluid shall I use? (DOT3,4,5?), and how much - also I assume it would be a good idea to drain the system before adding new fluid? - how do I do this correct?

Is it normal that the system gets drained over time, or should I start looking for leaks?

Looking forward to your input

Thanks!

Martin

 

[JohnB]

I would look for leaks. Then start with bleeding the master cylinder and the RR, LR, RF and LF. Make sure the master cylinder always has fluid in it.

 

[Rich 5150 69]

after checking for leaks, my guess is a wheel cylinder, if not are you running a power booster, if it is leaking vacuum it will draw brake fluid out of the master.

 

[vwnate1]

Use DOT 4 if you can find it .

DOT 3 is pretty good , DOT 4 has a higher boiling point , important if you have disc brakes are like to drive your drum braked truck in the hills at speed (ahem) .

Finding fluid leaks is opretty simple , remove the brake drums and *gently* lift the edge of the rubber dust boots on each end of each cylinder ~ any wetness means both cylinders on that axle are kaputi and need changing RIGHT NOW , prolly the shoes too as brake fluid on the shoes makes them grabby , I rolled a vintage car once due to this .

If you're going to replace two cylinders , take a moment to jack up and safely block the truck , scrootch underneath it and flex all three brake hoses , if even one tiny crack , replace ! .

Then find a 6 point box end wrench that fits the bleeder nipples on the other two brake cylinders and see if you can open and close them ~ do not snap them off , if they're stuck STOP , get a ball peen hammer and SMACK them dead on to shock the rust loose , try the 6 pointed box wrench again .

Still no joy or one broke off ? no worries , you didn't really want to die horribly in a mangled fiery collision anyway....

Remember : never , EVER turn or machine those old brake drums ! .

 

[mp8200]

Thanks for your feedback! - I'll try to look for leaks in the weekend!