I don’t recall ever having to replace a combination valve in my life – except for ones that were left outside in the elements (disconnected) or damaged from dropping an engine on it, etc. (which I, um, have been guilty of doing both . . .).
Brake hoses – I have had more than a few burst on me.
If a hose is 10-15 years old (or exact age is not known) and I’m servicing the brakes – I will replace the hoses, no questions asked. Most cases, they are cheap ($10-15 each) – which is a whole lot cheaper than body work and/or getting your britches cleaned after one busts.
I heard someone mention that a good way to prevent ABS problems on cars, it to use the ABS system about once every month or so (ie: slam on the brakes).
Most people do not apply brakes hard enough, often enough to make sure it all works.
It is my belief that some ABS components die from non-usage.
Also – it is very important to change brake fluid every couple of years or so because brake fluid attracts water moisture.
Water and metal = rust (or corrosion).
Rubber seals rubbing against rust (or corrosion) = seal wear.
I can tell when working on brakes – if the owner changes his fluid every couple of years (or not). The “not” owners are the ones who also has to replace calipers, wheel cylinders, etc. a LOT more often those people who change fluid more often.
Fluid is a lot cheaper than calipers and wheel cylinders and so forth.
BrotherGood, you have me wondering, now. What or why have you been thinking your combination/proportioning valve(s) have been failing?
I’m not disagreeing that you have bad valves – but trying to understand what is going on (or possible mis-diagnosis).
BudW