Brakes and my breaking point!

[edleibman]

Hello and please forgive me if this has been asked before, but endless searching and reading has not helped.

My brakes (namely front brakes) on a 1969 Series IIA 88" lock up in a most strange fashion.

When the car sits for a while, pedal travel is normal, perhaps a little long. A couple of pumps and the pedal travels less and less. Finally, there is no pedal travel, and the brakes are fully engaged all the time, it takes a fairly good amount of power to move the car.

Car sits a while again, the situation repeats itself.

I have all new cylinders, shoes and hardware.

My question is has anyone ever experienced this?

Is this a hydraulic issue? Is this an adjustment issue? I am my wits end and would be very grateful for your help.

[scott]

Have ya messed w/ the mc lately?

[edleibman]

Not since I installed it. What sort of fault were you thinking it might be?

(oh and ironically, I have a 77 Spitfire as well)

[scott]

i installed a new mc for my clutch. maladjusted it such that the fluid was not bleeding back completely after each engaging. during my test drive the pedal got firmer and firmer till the flex line to the slave blew while i was giving the pedal all i had to get it to depress. it seems that there's a valve of sorts on the mc that allows the fluid to move back into the cylinder ones the piston returns to the proper rest position

[gudjeon]

Free play adjustment between actuating rod and cylinder in the M/C? Sounds like it is at zero right now.

[bobzinak]

You din't memtion how long you have owned your rover. If at some time in its life some may have added the wrong type of brake fluid. (not castrol) petroleum brake fluid will detereorate the the naturaal rubber used in rover brakes. this includes the flex lines going to your front brakes..what happened to me is that particles of rubber were stuck in the brake hoses and would act as a one way valve by the particles floating to the top of the line and acting like a one way valve. pressure would bleed off slowly,sometimes, other than removing the lines and cleaning them out,(short term fix) it would be best to replace them. you could open up the bleed valve and release the pressure off the slave cylinder of one front wheel and see if the wheel spins easy..just my 2 cents..bobzinak

[LaneRover]

I agree with the deteriorating rubber lines theory.

[edleibman]

Thanks everyone for the replies. I did leave out a couple of points, one is that my master cylinder is the dual type (sometimes called later type I guess). I wonder if it can have a fault on one side?

Also, I am intrigued by the deteriorating rubber theory. How can I test for it? Should I be able to see particles?
I put in new brake fluid a year ago and thought it was to spec, but could have been wrong.
Again, many, many thanks... I feel my sanity slowily returning

[Jeff Aronson]

I had a '78 Spitfire for 10 years in the 90's - loved it!

Brake fluid should look amber in color, like light maple syrup. Bleed some out of a brake cylinder. If it has any gray shade to it, then you have deteriorating rubber in the fluid.

Jeff

[LaneRover]

Take the rubber lines and bend them pretty tight. If you have cracking on the outside they should be replaced even without deterioration on the inside. I had a similar problem on my 58 107. If I could get on the highway without using the brakes too much I was fine. But pressure would definitely build up.

Brent