KZJ70 Advice

[Roger Fairclough]

Have you set it up?

Roger

 

[Yorkshire Devil]

Yes It's just plug and play !

 

[Yorkshire Devil]

Is it this part which Milners sell? They list it as Brake Load Sensing Valve

http://www.milneroffroad.com/toyota...j70-brake-load-sensing-valve-oem-genuine-part

Has anyone got a plumbing diagram for the valve? And the brake lines? There are two lines from the front but which goes in what port? Why has the valve got a arrow on one port? The valve looks slightly different from the original

 

[Roger Fairclough]

From your previous post, I assumed you had fitted it and it was all working. Have you got a problem with it? Can you show us pictures of it fitted?

Roger

 

[Yorkshire Devil]

Brake Problem

Picture is fitted but I was wondering the significance of the two ports and if any sequence must be followed. Seems to work fine back brakes are spot on but the front are just above efficiency. Car has been bled numerous times through all bleed points. Could there still be air present in the master cylinder even if litres of brake fluid and bleeding has been done?

 

[Yorkshire Devil]

Brake Valve

If you can see the image of the Milner stock part which is clearer than mine, there is an arrow on the valve body and I just want to confirm I have used the correct port. The axle port is obvious but would it make a difference on the two pipes coming from the front which went into the two ports?

 

[Roger Fairclough]

I assume that you put the two pipes from the front into the same inlets as the original ie top pipe top hole etc. There is a bleed nipple on the valve. Have you bled this out? To check for air in the system, you need to clamp off the brakes at or near the calipers/drums. The brake pedal should feel solid. Please report back when you have done this.

Roger

 

[Yorkshire Devil]

Hi Roger would it make a difference if the ports got mixed up? Can there still be air present in the brake master even if litres of fluid has gone through in the bleeding process?

The front pipes have been clamped and checked and the valve has been bled too.

 

[Roger Fairclough]

If you clamp off the front and rear brakes (clamps onto the rear hose ---reducing hose to back axle--- and hose from chassis rail to front axle diff. case), the brake pedal should feel solid.

Does it?

Yes, there can be air present if bleeding is not done properly or if bleed screws used in wrong order or bleed screws not uppermost in whatever you are bleeding.

The two pipes from the front should not flop about when you disconnected them from the valve, so should have lined up with the new valve when you bolted that to the chassis rail. I don't see how you could have got them the wrong way round, so I don'y know what would be the result if you did, but it may be why you have a soft pedal ( have you got a soft pedal? )

Roger

 

[Yorkshire Devil]

The Milner genuine valve had the bleed nipple in a different position, but was a genuine Toyota part. I just wondered if anyone know which pipe specifically went in which hole.

 

[Yorkshire Devil]

No soft pedal just brake fade at speed. The pipes have been replaced before and it doesn't look as though they could have been mixed up but I thought I would check.

 

[Yorkshire Devil]

As the new valve was slightly different I wondered if the feed was in a different position.

 

[Roger Fairclough]

The purpose of the valve is to apportion the oil pressure allowed to go to the rear brakes. The greater the weight over the back axle, the greater the grip the tyres have and the greater proportion of the braking effort can be past to the rear brakes.

Your rear brakes are so big that they wont fade (unless you have crap linings ie cheap rubbish ). If the pressure is to much they will just lock up. If your front brakes are fading then there are two reasons. Crap pad material or you are overworking them. If the valve has not been set-up to correctly proportion the pressure, then either the back brakes will lock up each time you brake above a certain limit or they wont brake to the limit available. See my comment on the 6th May.

Find a quiet road, straight level and traffic free. Make certain your h/brake works. Clamp off the front brakes. Drive at about 15mph and brake. If nothing happens the rear brakes are not getting any pressure. You need to adjust the operating lever so that the section pushing up into the valve is higher. The lever operates a plunger within the valve. Plunger fully down, no pressure, fully up, max. pressure. You need to adjust the position of the plunger so that at normal foot pressure the rear brakes are working hard but not locking up.

Roger

 

[Yorkshire Devil]

Hi Rog,

Valve is all setup and working properly. Vehicle has been tested on a rolling road and bake brakes & handbrake are A1, HOwever the front brake efficiency isn't as good as it should be. It was ok prior to valve fitting but to be on the safe side new discs callipers and linings were replaced.
There is an element of bedding In to be expected but on the rolling road test the front brakes measured just above efficiency.

Would it prove prudent to bleed the reservoir pipes?

 

[Roger Fairclough]

I assume the technician used the brake tester on an MoT set-up. If so, he should have told you if the pedal was soft or needed setting up and as he didn't!!! I assume that is not the issue, therefore further bleeding is not required.

This leaves the front brakes.

The front brakes are also "heavy duty" in that they are large and the vehicle is slow. There is plenty of reserve power, so much in fact that the brakes run relatively cool. If the new pads require more than normal heat to begin to work properly (F1 car brakes approach 1000deg C before they start to work, hence the ceramic discs )then this could be a problem. In my opinion, anything other than std pads and discs is a waste of money.

Lastly, what condition where the discs in? The greater the wear, the longer it will take to bed them in. The above efficiency rating on the dyno proved that they work ok at 5mph but what pedal pressure was required to do it?

Roger

 

[Yorkshire Devil]

Hi Roger,

Yes it was tested on mot brake machine, mechanic has suggested master cylinder may be faulty.

Everything appears ok in operation and tests ok but efficiency is down and was down when old pads/calliper & discs were fitted.

 

[Roger Fairclough]

If you isolate the m/cyl. by clamping off the hoses, the pedal should feel solid. If it isn't or there is creep as you maintain a high pressure on the pedal, then yes, the m/cyl. is suspect.

Roger