Hi guys,

Having issues with a 40/40 prop valve on my Civic, I bought the unit brand new a couple years ago, but only this weekend got to trying to bleed the system, first I had the master cylinder fail, so had to replace that, so I got a DC2 master cylinder and booster for it. That fixed the leaky master issue, then spent many many more hours trying to pull fluid to the rear right caliper to no avail.

At this point I started to remove the lines from the prop valve one by one to see what's what, turns out the 2 rear output ports were dry as a bone while both fronts and inputs from master were wet and had fluid present. So eventually I removed the prop valve and sprayed brake cleaner into the input and output ports, and sure enough fluid came out of the front ports but nothing out of the rears ? Not sure if this was normal, I went to find the original (drum brake version) and did the same with that, spraying fluid into the inputs on this one resulted in fluid running out from both front and rear ports on the prop valve.

SO the question is, do I assume this new prop valve is simply faulty/failed ? OR is this considered normal on a new unit.

For context, the car is running a full DC2 brake setup with braided lines throughout, 282 front and 262mm rear discs, new EK9 calipers on the rear, rebuilt calipers on the front. New master cylinder and refurbished booster. The new prop valve was purchased at the start of the project about 2yrs ago so has been on the car dry for some time, though never sat with open ports, always connected to the lines.





this shows the route of the brake fluid I sprayed into the rear ports from above. Old one it flows out, new one it goes nowhere

 

Its upside down. Mc inputs should be on top so flow can go down to each brake line.

*Nvm its not upside down. Try using an evacuator thats air powered to pull the fluid through.

 

Also make sure the all brake bleeders are on top of the caliper(highest point) to remove air. If calipers are installed on the wrong side(which it will fit) the bleeder would be on the bottom where you cant remove air.

 

Its upside down LOL you almost had me.....

In other news I managed to solve the problem, the prop valve itself had failed, both the limiter pistons inside had seized solid, I took it back to the supplier ( japserviceparts in the UK) and they swapped it for a new one, and that worked perfectly right off the bat, I had fluid in the furthest rear calliper within about 4 pumps of the pedal. So its clear now that I lost 4hrs of my life fighting against a faulty part!

Ah well it happens sometimes. The good news is the car now runs and stops under its own power !!!! Wheel alignment, MOT (uk safety test) and Dyno Tune all booked I cant wait to drive this thing for the first time Damn, it got through some fluid to fully bleed though, had loads of air in from all the messing about before.

 

Oh man, that's an expensive pile of empty bottles...

That's a fantastic looking build. Did you build the brake soft lines yourself?