Brake Pedal becoming hard to press and brakes failing!

[Lummox]

The brakes on my 2006 T350 90 Transit 2.4 suddenly started playing up after oil go into my vacuum system when the vacuum pump failed. I had the pump replaced and got great suction and bled the brakes. The brakes seemed ok on first press of the pedal but on the 2nd press it got hard and the third press solid and no brakes! Then all of a sudden they went back to normal again until you pressed a few times in quick succession and wallop still no movement at the pedal and little if no brakes!

So back she went to the garage and a new master cylinder and new servo fitted.

Exactly the same! The mechanic now says all the new parts are working OK on the rolling road as soon as you get it on the road te problem recurs.

I'm now thinking new slave cylinders and new brake lines???

What would cause the solid feel and no no downward movement at the pedal? The suction was mega strong after fitting the new vacuum pump. Hope all the pipes joined up correctly around the T?

Help!

[metalworker0]

Well they are a poor garage if all they can do is fit parts , and not cure your problems.

I don't know all transits and all fitments and nothing specific about any transit ..other than connects
Only know general info on all vehicles //
i think it could be the "brake pressure differential valve" ..also called a proportional valve ..that's what you need to look at next ..
but don't get that garage to do it ..as they are clueless .

Rock hard pedal is one of the symptoms of this valve failing.
The valve can "trip" meaning stuck over to one side , and needs a reset

but still could be something else ..I'm just saying ..that would be my next port of call.

This is not an instruction to just keep chucking parts at it ..until you find the solution ...a decent garage should have known what the fault is from the onset..

all the best.mark

[Lummox]

Mark I think your spot on mate.

FORD TRANSIT MK6 MK7 LOAD SENSING LADEN LOADING VALVE 2000 TO 2014 2.0 2.4 £89. Do you think its easy to fit?

Looking at what this does its defo the next port of call. Its and old van 2006 150k miles but I've replaced diesel pump, injectors, vacuum pump, servo, master cylinder, tyres, water pump so slowly she's being restored!

thanks again mate

[metalworker0]

not what i meant ..well give it a try , cant see the thing i was on about on the parts diagrams ..perhaps they don't come with anti lock brakes,.
The thing i was on about is a hydraulic unit ..

but if that things capable of causing brakes to malfunction in the way you describe ..work it out before hand...it may only need freeing off and lubing

[metalworker0]

Never mind ..i was wrong, that is a hydraulic device ..the one i looked at on ebay didn't show the hydraulics.
Probably does exactly what i was thinking, probably defective internally ..and any cleaning or lubing will not help.
so replace and prey ..because the next thing is the ABS unit

as regards fitting ....you have 4 hydraulic connectors ...each one could be seized onto the pipe ..so unscrewing them could twist and ruin the pipe, so use some heat if it feels like that ..and best unscrewed with a brake spanner rather than an open ended spanner.
They may also (don't know) be a funny size like 11mm

all the best.mark

[Frag]

Have you checked or replaced the vacuum pipe from the vac pump to the servo ?

[Lummox]

Right lads so I'm now thinking of getting this ....

FORD TRANSIT MK6 MK7 LOAD SENSING LADEN LOADING VALVE 2000 TO 2014 2.0 2.4 £89.

However, does my van have one? Does my old van have ABS?

Where would I find it? So I can at least confirm its there before I buy it!

Thanks and happy new year !

[Lummox]

https://www.transitparts.co.uk/collecti ... -2000-2014

[metalworker0]

To confirm it has ABS ..there should be a orange light that comes on on the dash (it's on the right hand side on mine) ..with the letters ABS when ignition turned on ...it then go's out once started.

laden valve - the guys here will confirm that it has one ..on your 2006 T350 90 Transit 2.4

all the best.mark

[metalworker0]

Not enough people here answering and inputting info into this problem

please wait for more answers from those more knowledgeable than me.

they may save you some time and money!

all 5the best....mark

[fortyeight]

if that garage put all them parts on,tell them to take them off and refund you as it as not cured the fault,and use a different garage

[Lummox]

Right lads I got under the back of the van today and cant find a load sensing proportional valve anywhere?

There did seem to be a junction box type jobbie but no long spring loaded steel arm etc?

Do they all have them?

Phil

[metalworker0]

been told that valve is only on the mk6

a parallel conversation on the same problem is happening in the mk6/7 forum

with still no real answers ..is this you under another name?

viewtopic.php?f=5&t=220576

all the best..mark

[knobby1]

Right lads I got under the back of the van today and cant find a load sensing proportional valve anywhere?

There did seem to be a junction box type jobbie but no long spring loaded steel arm etc?

Do they all have them?

Phil

If you have ABS, you won't have a load sensing valve. If you have ABS, you'll have tone rings and ABS sensors at each wheel.

Lord Knobrot

[Lummox]

No that wasnt me under another name on that over thread but very similar problems!

I posted this...

Blimey this is exactly my problem, Brake normal on first push, stiff on second rock hard on third, no brakes!
I have renewed master cylinder, vacuum pump, brake servo. Still the same. Just failed MOT on the brakes, 46%.
He said its uneven pressure being delivered to the slave cylinders. Pass front and back locking up when driver side not?
Mine is a 2006 Mk6 T350 90 RWD LWB and it dosent have a load sensing proportional valve just a junction box splitter type arrangement. Does that mean its ABS?
It does also have corroded brake pipes covered in grease?
Dunno what else to replace!

Apparently there is a brake pump thats not the brake vacuum pump?

What actually decides what pressure goes where as mine is locking up yjr fromt and back on the passenger side only?