Brakes: 140: Brake valve alternatives

[Triple-S]

Having just replaced all the brake pipes, flexibles and master cylinder on my '68 142S, I still have naff fluid flow at both rear caliper bleed nipples, despite compressed-air assisted bleeding. As the front all squirt fine I am deeply suspicious of the bleed valves which fit under-floor just in front of the back axle.

The question: I have a pair of spare valves from a 240 estate, part-numbers unknown. According to my "Volvo 140 part numbers book to 1972" my car has #677588-6 on the left and #677589-4 on the right. However, it also states the 144 range has #680344-9 left and #680345-6 right, implying there are differences.

Does anybody know what these differences are, and if 240 estate ones will be a good substitute - they look the same, maybe its to do with spring strengths?

I'm assuming mine are beyond repair; anyone overhauled these, so can advise on problems?

TIA

Paul

[john h]

Paul

Can't help you with rebuilds etc, but I had a thought:

Are you doing this work with the car jacked up and the rear suspension on full drop? If so, the valves would interpret this as rear wheels lightly laden and at risk of locking and they would therefore, correctly, limit flow to the rear brakes.

Better jack the axle instead of the car body and have the car at its normal level.

(Sorry if this seems an obvious point, but just thought I'd check!)

Good luck

John

[Sam Barker]

Hi,
Do you have fluid up to the brake valves and beyond them? I bled mine through by cracking the unions open and watching them bubble for a while. It makes a mess you've got to clean up but with my Alfetta it made a difference, since then I've always done it, and didn't have an issue. If pressure bleeding I suppose you could check both sides of the valve too, find the restriction.

Sam

[Derek UK]

John H. These are just pressure limiters and don't have an arm attached to the axle to alter it as the nose dips under braking.
Paul. Late 140 numbers are L 1212496-2 and R 1212477-2. These mount to a bridgeing plate between them. Includes 145.
The numbers you give for yours are also the numbers, 2 sets, for early and late 164 and are the same as B20 Amazon with dual circuit brakes. These have the mount cast in and have a seperate bracket for each. The way they are mounted might be the only difference.
Service kits NLA but you could risk taking them apart for a good clean. Removing them completely would just give you more rear braking with a risk of premature lock up. A safety risk there but would probably please your MOT man when he tested the brakes. Don't know about early 240 ones, their numbers might be the same as the late 140 ones but if the fittings are the same I'd think that any of the basic types would do the job.
I know you're a "cruiser" and don't use the brakes much anyway...............

[Triple-S]

I've been called many things, Derek, but never a cruiser! Also, if I had still been a "motorway burner" or a scorcher-away-from-the-lights hero I'd have gone modernish with my day-car, rather than a 740 auto!

Thanks for numbers, also for relation to 164s (which I didn't know): I ought to have looked in my 164 parts book before asking - makes me feel a bit of a numbscull now!

After taking my units off I'll compare with those from my scrap 164, but a small question - does it matter which brake pipe from the front goes into which unit? Thats because there were no brake pipes on my project behind the master cylinder, as the previous owner said he was having caliper troubles.......

Paul

[Derek UK]

The parts book should give you the layout but I only have a late 140 one. Unless you've gone to town with the underseal, I'd think that you be able to see where the pipes were fitted originally.