Overhaul of brake proportioning valve?

[macabethiel]

Thanks Ted, I will have a look. Will initially just use it without the brake portioning valve and see how it behaves. Another valve is quickly installed if required.

You should be okay in the dry but in the wet you might find the rear brakes keep on locking up - not good you could easily end up spinning off the road on a bend!

 

[Banshee]

In the end I cut the pipes near the crossmember and pulled the valve out.

Installing a T piece to go from 2 brake pipes to one but that has to wait till tomorrow.

Nice work sir!!! As I've stated previously, my Maverick didn't misbehave in the wet after I'd removed this but worth a try all the same to see how your individual truck behaves especially being a different model.

I'm sure you'll be fine though :thumb2

In terms of an MOT, a tester can't test what's no present :augie :naughty :thumb2

 

[Flying Torquewrench]

Everybody’s advice is always greatly appreciated. That is what keeps the forum going and it is nice to see some discussion. :thumb2

Under no circumstance will I put a car on the road that is dangerous. Not because I am scared to injure myself but more to avoid injury to others. Especially because I nearly always tow a heavy trailer with it so it needs to be safe.

If it turns out that a proportioning valve is required than it will be installed.

In all fairness Banshee, I am not sure if it will see an MOT inspector in the next few years. Depending on my job situation in the new year I am looking at a replacement for the Patrol.

Hopefully in the next couple of years I will have the facilities in which I can do a nut & bolt restoration on it. But we first need to get rid of this bloody virus so that the aviation industry gets back to normal.

 

[Banshee]

Everybody’s advice is always greatly appreciated. That is what keeps the forum going and it is nice to see some discussion. :thumb2

Under no circumstance will I put a car on the road that is dangerous. Not because I am scared to injure myself but more to avoid injury to others. Especially because I nearly always tow a heavy trailer with it so it needs to be safe.

If it turns out that a proportioning valve is required than it will be installed.

In all fairness Banshee, I am not sure if it will see an MOT inspector in the next few years. Depending on my job situation in the new year I am looking at a replacement for the Patrol.

Hopefully in the next couple of years I will have the facilities in which I can do a nut & bolt restoration on it. But we first need to get rid of this bloody virus so that the aviation industry gets back to normal.

Good man, I like your ethics!! If anything, with a heavy trailer weigh laden on the vehicle pushing the rear down, that would be enforcing maximum braking efficiency via the load sensing valve which is what you'd be achieving 24/7 with the mod you're going to do. The only difference is all the weight isn't going to be there behind you.

I'm wondering how long it's going to be before mine see's a test station again........

See my project thread :doh

 

[Flying Torquewrench]

Very true Zac. That is why I am not too worried to drive without the valve but it must be safe. Only just seen the Terrance the Terrano thread. :doh:bow I have some reading to do. :thumb2

I fitted the T today and bled the brakes All looked fine but the brakes don’t want to firm up. So there is either a bit of air trapped in the system or a small leak. Unfortunately my chief brake bleeder had other things to do :doh The Patrol spends another night in the garage.

 

[Flying Torquewrench]

Scratching my head at the moment.

Bled the brakes again today and there is no air in it whatsoever. However the pedal is firm when the engine is not running and has full travel (with some resistance) when the engine is running. To stop it from about 20 mph I can press the pedal to the floor and it comes to a gentle stop. This can’t be right.

Rick or Zac, how did you route the pipework after removal of the valve?

I have taken the valve out and inserted a T piece to combine the two brake lines that come from the front to the back into 1 brake line. I am not wondering if I should route each pipe that comes from the front to an individual brake? My reasoning being that it now might pump the brake fluid round.

What do you guy’s think?

 

[Wallace]

Follow the lines back up the car and see where they go, it might be a diagonally split system. Can you find a circuit diagram?

 

[Flying Torquewrench]

The lines all come from a block next to the engine. 2 go to the front brakes and the other two lines run to the back.

It used to be 2 lines going into the brake proportioning valve with one line coming out. This one line goes through a flexible pipe to the top of the rear axle. Here it splits to 2 lines which go to the LH & RH brake.

I replaced the brake proportioning valve with a T. But I winder if I now pump fluid around instead of getting braking action. I will remove the T and just run 1 pipe as an experiment. If that works then I will buy another flexible brake pipe and run each side individually.

 

[Wallace]

Interesting, how is the block fed from the master cylinder/servo?

 

[Flying Torquewrench]

In all fairness Wallace, I haven’t looked at it yet.

Just doing some research online and it appears that the brake proportioning valve has 3 connections. 1 inlet, 1 outlet to rear brakes and 1 return so it can modify the amount of brake pressure to the rear brakes. By putting a T in the line I have connected the inlet to the return so there will never be any brake pressure on the rear brakes.

The T is coming out tomorrow and I will blank the return line. See where we go from there.

 

[Wallace]

I took a guess at yours being a Y61 and found this schematic, it may not be correct for your vehicle but shows a feed from the front and rear going to the bias valve from the 5 way block. Interesting to see the other part shows ABS with the bias valve so at a guess the ABS is only on the front brakes.

 

[Wallace]

Not sure the picture views very well, this might be better.

 

[Barrbeast]

Nah Y61s with ABS definitely have it on all 4 wheels

 

[Flying Torquewrench]

Thank you Wallace. That explains perfectly where I went wrong.

Need to order a blanking plug so I can cap off the return line.

A selection of male/female blanking plugs are ordered and hopefully they arrive tomorrow, depending on Royal Mail.

 

[Flying Torquewrench]

Royal Mail arrived today with a package from Car Builder Solutions containing 4 male blanking plugs and 2 female blanking caps. :thumb2

 

[Wallace]

I hope you get a good result. :thumb2

 

[Flying Torquewrench]

Removed the T section again and connected the inlet and outlet. Blocked off the return pipe and so car everything seems to working just fine. Even in the rain the rear wheels do not lock up at all. :thumb2

Whilst playing around with the brake tubes the hand brake warning light came on and wouldn’t go off. Now I know that the hand brake has absolutely nothing to do with the normal brake system as the hand brake brakes the prop shaft. It was just a coincidence. Adjusted the hand brake warning light switch and all was good again.

 

[Barrbeast]

Removed the T section again and connected the inlet and outlet. Blocked off the return pipe and so car everything seems to working just fine. Even in the rain the rear wheels do not lock up at all. :thumb2

Whilst playing around with the brake tubes the hand brake warning light came on and wouldn’t go off. Now I know that the hand brake has absolutely nothing to do with the normal brake system as the hand brake brakes the prop shaft. It was just a coincidence. Adjusted the hand brake warning light switch and all was good again.

Sounds like it was the switch then but watch next time dude as the hand brake light comes on to indicate low brake fluid :thumbs

 

[Banshee]

Well done Mr Torquewrench

 

[Barrbeast]

Oh yeh, good work too dude