16 replies to this topic

[Steve8274]

I think thats what its called anyway. The brake bias on front bulkhead. Just realised its the fam7821
Is there a way to test if this is ok prior to putting it back on car? Was working fine when it was removed but its been stood for few years. Indoors in a warm dry environment.
Thanks

Edited by Steve8274, 08 March 2018 - 05:40 PM.

[Retroman]

My test for them is see how far I can throw them and get them in the scrap skip.

 

Sorry, hate them and never put them back on, they make the brakes a pain to bleed up, and there is no test (that I know of ) to say they are working or not either on the bench or car.

  So you can risk fitting an unknown quantity that has been dry for how long and not knowing if it works as intended or not.

They were a pointless idea in the first place and achieve nothing but unnecessary complication...

Like EGR valves cats automatic headlights, automatic wipers and electric handbrakes, 10 out of 10 for novelty value.

Apologies for the rant but I tend to from the Issigonis simple school of no radio, the ICE is under the bonnet.

[Steve8274]

What do you use instead then? Surely it must serve some purpose?
My car has the new type master cylinder so wont it put too much braking power to the rear if not fitted?
Sorry for all the questions.

[Ethel]

Fam7821 uses the front circuit pressure to close off the rear circuit at a particular pressure differential. So, if you lose the front circuit, there'll be no limiting of rear brake effort and a failed rear circuit will be sealed off, reducing fluid loss and improving the effectiveness of what brakes you have left. Junking one could lead to some awkward explaining if the worst has happened and you needed to use your insurance.

[Retroman]

Are you sure ?

If you loose the front brakes you are knackered anyway, it happened to me at 15, no valve to close of the rear circuit will save anything. The chances of losing your brakes these days are virtually Zero.

They are a theoretical impractical nighmare that can't be tested (to my knowledge).

Sorry Ethel your explanation is confusing.

Using an unknown probably un-testable braking item that is not needed is safe?

[Spider]

I'm with the Retroman all the way on this and them some.

 

They are an ingenious piece of crap to say the least.

 

What do you use instead then? Surely it must serve some purpose?
My car has the new type master cylinder so wont it put too much braking power to the rear if not fitted?
Sorry for all the questions.

 

Two options using factory bits.

 

1. Fit the old type shut off valve that was originally fitted to the front rail of the rear subframe.

 

2. Fit the one that came after that, the Inertia type Valve.

 

There are also some after-,market option too.

[Steve220]

I really want to get hold of an old one and slowly pull it apart. Intrigued as to their mechanical operation and why the fail so regularly!

Edited by Steve220, 09 March 2018 - 10:54 AM.

[Steve8274]

I'm with the Retroman all the way on this and them some.
 
They are an ingenious piece of crap to say the least.
 

What do you use instead then? Surely it must serve some purpose?
My car has the new type master cylinder so wont it put too much braking power to the rear if not fitted?
Sorry for all the questions.

 
Two options using factory bits.
 
1. Fit the old type shut off valve that was originally fitted to the front rail of the rear subframe.
 
2. Fit the one that came after that, the Inertia type Valve.
 
There are also some after-,market option too.

Do you mean
http://www.minispare...74.aspx|Back to
Or
http://www.minispare...|Back to search
Or something else. How do these fit and do I need to redo brake pipes. I have just finished re doing them all.
Thanks

[Retroman]

What do you use instead then? Surely it must serve some purpose?
My car has the new type master cylinder so wont it put too much braking power to the rear if not fitted?
Sorry for all the questions.

 

Please don't apologise for the questions....it is a safety critical component.

 

The simple way to replace it is to use 2 M10 straight female joints on the bulkhead where the 'thing' sits.

 

This then creates a more normal simple Mini system with a front / rear split as per the twin line type master cylinder which you are using.

 

The T piece on your rear subframe then needs replacing with a conventional type Mini pressure regulator valve or an after market one.

 

Its a simple known solution, cheaper than a new pdwtf valve

 

PM me if you want the kit.

[Steve8274]

What do you use instead then? Surely it must serve some purpose?
My car has the new type master cylinder so wont it put too much braking power to the rear if not fitted?
Sorry for all the questions.

 
Please don't apologise for the questions....it is a safety critical component.
 
The simple way to replace it is to use 2 M10 straight female joints on the bulkhead where the 'thing' sits.
 
This then creates a more normal simple Mini system with a front / rear split as per the twin line type master cylinder which you are using.
 
The T piece on your rear subframe then needs replacing with a conventional type Mini pressure regulator valve or an after market one.
 
Its a simple known solution, cheaper than a new pdwtf valve
 
PM me if you want the kit.

Many thanks for replying. I think I will go down this route. Are the pressure regulators like the ones I linked above? Are any better/more reliable than the others? I dont suppose you have a photo of one in situ?

[Spider]

 

I'm with the Retroman all the way on this and them some.
 
They are an ingenious piece of crap to say the least.
 

What do you use instead then? Surely it must serve some purpose?
My car has the new type master cylinder so wont it put too much braking power to the rear if not fitted?
Sorry for all the questions.

 
Two options using factory bits.
 
1. Fit the old type shut off valve that was originally fitted to the front rail of the rear subframe.
 
2. Fit the one that came after that, the Inertia type Valve.
 
There are also some after-,market option too.

Do you mean
http://www.minispare...74.aspx|Back to
Or
http://www.minispare...|Back to search
Or something else. How do these fit and do I need to redo brake pipes. I have just finished re doing them all.
Thanks

 

 

Yeap., either of those. I do actually prefer the latter, but they are more fussy to fit as the fitted angle of them is important.

[Ethel]

Are you sure ?
If you loose the front brakes you are knackered anyway, it happened to me at 15, no valve to close of the rear circuit will save anything. The chances of losing your brakes these days are virtually Zero.
They are a theoretical impractical nighmare that can't be tested (to my knowledge).
Sorry Ethel your explanation is confusing.
Using an unknown probably un-testable braking item that is not needed is safe?

I agree it'll be a brown trouser moment with no front brakes regardless. I'm also a fan of the inertia valve, but insurers are mostly interested in protecting their profits, you could have a scrap on your hands justifying a modification from original equipment after the event. Remember that untestable item was original equipment that superseded your alternatives. 
 
You can find details of the Fam valve online, Landrovers in Moke's part of the world if I remember correctly...
 
You can almost work it out from the outside layout - Return spring in the pressed steel end, front circuit pipes are inline and "on top" of the shuttle piston. The rear circuit pipes are offset so the shuttle covers the inlet while leaving the outlet unobstructed so the residual pressure in the line to the rear can help reset the shuttle when you let  off the pressure to the front brakes.

I'm not contradicting you just trying to offer the OP an informed choice

[Ethel]

Inertia valves were standard equipment on vans, I'm sure I've seen photos somewhere, but where? 

[Retroman]

 

 

What do you use instead then? Surely it must serve some purpose?
My car has the new type master cylinder so wont it put too much braking power to the rear if not fitted?
Sorry for all the questions.

 
Please don't apologise for the questions....it is a safety critical component.
 
The simple way to replace it is to use 2 M10 straight female joints on the bulkhead where the 'thing' sits.
 
This then creates a more normal simple Mini system with a front / rear split as per the twin line type master cylinder which you are using.
 
The T piece on your rear subframe then needs replacing with a conventional type Mini pressure regulator valve or an after market one.
 
Its a simple known solution, cheaper than a new pdwtf valve
 
PM me if you want the kit.

Many thanks for replying. I think I will go down this route. Are the pressure regulators like the ones I linked above? Are any better/more reliable than the others? I dont suppose you have a photo of one in situ?

 

 I don't have any photos to hand, the only valve currently available is the adjustable type which can't be fitted in exactly the same position as the normal one. The adjuster comes out of the smaller end, which in a normal fitment goes in the hole on the rear subframe. So unless you can source a standard one the only option is adjustable. I can do them a few quid cheaper than MS too. their part No is MS72.

[Steve8274]

Seen as it was mentioned about the fam valve being fitted to other vehicles, after a little search, I came across this one in link
https://www.lrdirect...randed-oem.html
It looks the same and is cheaper than minispares or any other mini supplier I have looked at.
Is it the same?