BRAKE PRESSURE REGULATING VALVE

[BIG E]

Hi Guys, I have a few comments on the merits of the rear Brake Pressure Regulating Valve. As I understand its principle of operation is to prevent the rear brakes locking up in advance of the front brakes under varying loads and conditions at the back end. If you fit lowered springs to your G like most of us have done you will have to adjust the valve operating linkage so that the correct pressure is maintained to your rear brakes under varying conditions and loads, and in principle preventing the rear brakes from locking up, drum or disc.  The question i ask is.  Is the valve really nessissary? Would the rear brakes lock up without it?  Do you guys who race the G have the valve fitted? If your answer is yes to these questions then why did VW make more Polo 1300 CLs than G40s & GTs without a pressure regulator fitted?  I have a workhorse CL Coupe 1300 J reg without one, and the brakes have never locked up under any situation or loading. I await your comments Guys. Thanks Big E.

[hardchargin40]

Racers had in-car adjustable AP Racing bias lever/valve.

Never had a problem with a normal one when lowering though.

Don't know about one without, never put too much thought in it tbh.

This may get moved to the brakes forum section btw.

[BIG E]

Hi there Hardchargin 40, Sorry for submiting my post on the g40 brake pressure regulating valve.  I did not realise your lack of technical knowledge and expertese on the G40. And not allowing any other members the chance to reply to my post, Shame, I had so much more good useful info on the G40 to submit on this forum. But hey whats the point. Big E.

[PeteG40]

calm down...

he did say he'd not had a problem...



the cls etc have different cylinders to reduce the effort to the back brakes.  put discs on and you'd get even front/ back power (ish) meaning 50/50 and you want like 70/30 or 80/20.  So definately if you fit discs you need a regulating valve, if you stick to drums, then use the cl cylinders not the gt/g40 ones

pete

[hayesey]

Hi there Hardchargin 40, Sorry for submiting my post on the g40 brake pressure regulating valve.  I did not realise your lack of technical knowledge and expertese on the G40. And not allowing any other members the chance to reply to my post, Shame, I had so much more good useful info on the G40 to submit on this forum. But hey whats the point. Big E.

what's that all about?  Paul just seemed to be answering your question to me, and it was posted in the wrong section. No need to get so worked up about it. 

I have a bias adjuster lever in mine but I also have 200mm drums and 4-pot calipers so I wanted to ability to t the bias manually since it's so changed from standard.  Otherwise you'll be fine lowering it, no one bothers to change the standard bias adjuster.

[youngprodigys]

i have an adjustable one on mine which replaced the original as my adjustable suspension altered the brakes when lowering it. after removing it and bleeding the new one in the brake were awful until i set it up to be about 70/30. so i can imagine it makes one hell of a difference. VW wouldnt put it in the system if it wasnt needed.

in in reply to what you put to hardcharging, you over stepped the mark to someone who respected on here- if you want to write things like that i suggest you try another forum.

[BIG E]

Hi Guys.
           First of all let me apologize for my outburst on Hardchargen 40s comments on my blog about the Brake pressure regulating valve. It was uncalled for, Unnecessary, and very unprofessional.
           Pete, Thank you for your comments they were very helpful and answered a lot of my questions. I now have the 256 Setup,Front Vecta rear mk4 golf and the larger brake master cylinder.  As you rightly said idealy i will need a 70/30 split for it to work properly. Will i need to fit gauges to achieve this or can i just tweek the linkage a bit at a time till i achieve a good setup? Thanks BIG E.

[youngprodigys]

go to an mot centre and set it up on the rollers, got to be the best way - and the safest

[BIG E]

Thanks ace i will do just that, you must have done that yourself then? Thanks BIG E.