Brake Pressure Reducing Valve

[Vegas_M]

Last night I was cleaning the Brake Pressure Reducing Valve in preparation for reassembling my brake system. The ports for the brake lines looked pretty gunked up so I thought I'd pull off the bolt cap and used some brake cleaner to clean the insides.

Well it was really gunked up inside so I started to spray in the cleaner. Suddenly I heard a little clink of something metal falling and hitting the ground. Search as I may, I couldn't find anything. Looking at the (now clean) open end of the unit the only thing I can figure out is that it was either a single ball bearing or a small loose pin. Either way, I have no real idea. Typical....[:(!]

I found a x-section diagram of a version of this device in an old Haynes manual, but it is a slightly different device. Pics below.

<u>Haynes style Brake Pressure Reducing Valve</u>


<u>My TR7v8's style Brake Pressure Reducing Valve</u>


Notice that in the Haynes style there is a brake pipe mounted to the bolt cap. In my style there is an extra port on the body of the unit, so the interior plumbing will be different.

So, does anyone have a blow up diagram of the components of my style of one of these devices or know what fits in the end?

Thanks for your help.


Martin

[url="https://docs.google.com/leaf?id=0BxOL0HRH5pDeNWRlOTVhZjgtMWE1Mi00ZWNiLWE3ZGYtOWNiODU1Y2JjOGQ0&hl=en_GB"]My TR7v8 Document Repository[/url]

[Vegas_M]

Guys,

The above issue is worrying me. I don't want to assemble the brake system, bleed it, and go for a drive only to have it fail because I'm missing something in the valve.

Anyone got a spare reducing valve that can take a look under the screw in cap and let me know if there is a pin or ball bearing fitted to the end of the apportioning assembly?

Thanks!




Martin

[url="https://docs.google.com/leaf?id=0BxOL0HRH5pDeNWRlOTVhZjgtMWE1Mi00ZWNiLWE3ZGYtOWNiODU1Y2JjOGQ0&hl=en_GB"]My TR7v8 Document Repository[/url]

[DNK]

Martin, call woody or Ted. They know, I am sure

Don
"No More Cars For You"
71 TR6- Perpetual remodel
80 TR7 V8 Kick in the pants

[Marko]

or you can scrap that thing , connect the front brakes directly to the master cylinder and fit one of these to the rear brakes.

http://compare.ebay.com/like/3503807010 ... s&var=sbar

and adjust to desired spec.


edit:

http://cgi.ebay.com/ebaymotors/TRIUMPH- ... ccessories

here's "new" one , but they are still old as our cars. Some newer equipment wouldnt hurt.

[bmcecosse]

Ive often considered getting rid of this valve - I did so on my Mini years ago to considerable benefit! Do the rear brakes REALLY need a pressure limiter in the circuit if the old valve is removed?

[Vegas_M]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Marko</i>

or you can scrap that thing , connect the front brakes directly to the master cylinder and fit one of these to the rear brakes.

http://compare.ebay.com/like/3503807010 ... s&var=sbar

and adjust to desired spec.


edit:

http://cgi.ebay.com/ebaymotors/TRIUMPH- ... ccessories

here's "new" one , but they are still old as our cars. Some newer equipment wouldnt hurt.
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Marko,

From what I've read, the stock valve is "variable" and reduces the percentage of pressure to the rears depending on how hard you stamp on the brakes. Thus they call it a "Pressure Reducing Valve" not a "Pressure Reduction Valve".

The adjustable valve that you link to on eBay is variable, but has a fixed percentage reduction once set.

But, knowing the Brits during the late 79's era, who knows what their unit actually does... Might be the same sort of thing. [^]

Martin

Martin

[url="https://docs.google.com/leaf?id=0BxOL0HRH5pDeNWRlOTVhZjgtMWE1Mi00ZWNiLWE3ZGYtOWNiODU1Y2JjOGQ0&hl=en_GB"]My TR7v8 Document Repository[/url]

[Marko]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Vegas_M</i>

From what I've read, the stock valve is "variable" and reduces the percentage of pressure to the rears depending on how hard you stamp on the brakes. Thus they call it a "Pressure Reducing Valve" not a "Pressure Reduction Valve".

The adjustable valve that you link to on eBay is variable, but has a fixed percentage reduction once set.

But, knowing the Brits during the late 79's era, who knows what their unit actually does... Might be the same sort of thing. [^]

<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">


thats the same thing,

Out of the master cylinder come 2 brake lines, since the brake master cylinder is the same bore inside, with your foot you create equal pressure on both outlets of the master cylinder.

Connecting the rear brakes trough a brake pressure reduction valve it reduces the pressure by some percent. So the reduction of rear brakes is always a percent of front brakes. You just need to dial it in by how much. That way the front brakes will always loose traction first during braking.