504 rear brake load compensator valve

frogs4ever

frogs4ever

Active member
Fellow Frogger
Joined
Jan 3, 2003
Messages
391
Location
Tasmania
Hi Guys and Gals,

I've been scratching around under my 1976 504GL and have noticed that the brake load compensator valve is leaky.

I've been quoted $247 for one suitable for an "early 504", and $90 for a "504/505" unit. The prices are for new parts.

Does anyone here know what years are considered "early" when it comes to brake compensator valves? Or does anyone know how to tell the difference between the two by visual inspection?

:confused:
 
early is for the single flare brake lines and late is regarded as the metric double flare brake lines
hope that helps

oh yeah
the double flare looks like a bit of a ball on the end on the line and the single flare is just a splayed out end on the end of the line

76 model should be double flare metric brake fittings

all early 504's had the front caliper on the back side of the disc and the late 504's had the caliper on the front side of the disc
 
Pugrambo,

My front calipers are in front of the disks rather than behind, so that suggests the later system.

I'll shall have another look to see what type of pipe fittings lead to my compensator valve.

Thanks for the quick and informative reply.
 
If you have the later brake lines, you will also have a plate or sticker under the bonnet that tells you that the lines are double flared... have a look for that.

And aren't all the double flared metric thread systems all fitted with the tandem master cylinder?
 
boodek:
Are there not repair kits available for these valves? New rubbers and so on?
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There may be repair kits available, but if an entire new unit is available for just $90 I'm not going to go through the pain of cleaning up and repairing a rusty old lump.

Last time I had a brake component (master cylinder) reconditioned it caused me nothing but hassle and resulted in me falling out with a good mechanic. I really should have spent the few extra dollars and gone for a brand spanking new one. The small amount of money saved by having a kit fitted was quickly eaten up by taxi fairs, phone calls and alcoholic nerve calming agents.

Thanks for the tip though.
 
I've had another look, and yes I do have the metric, double flared system.

So I've taken a punt and ordered the "504/505" part from French Connection.

Dave at French Connection expressed surprise that the original part had failed, he said this is a very rare happening. I would say that it might have something to do with my driving combined with worn non-original rear shock absorbers. The two factors have possibly combined to result in the rear suspension bottoming, and also probably reaching the maximum extreme of its travel on rebound to, on several occasions. This would cause the rear compensator valve piston to travel backwards and forwards through extremities of the cylinder which may not have seen any action for many years prior to me purchasing the car, and hence corrosion in these areas has now destroyed the piston's seal. Just a theory, but sounds plausible to me.
 
Hi, it's not unusual for pressure limit valves to fail. When we had rego checks in the ACT 504's seemed to need valves every couple of years as it was one of their specials (to poke around and find the slightest weap). They do seem to have got better on later 504s and 505s.

Generally there aren't kits available. There was a guy in the Sydney pug club who did them up exchange but I haven't heard of him for years.

Cheers

Jim
 
This is very interesting..........

I am thinking that this compensating valve is the case of some of my rear brake problems.

I have adjusted mine till it is allmost off, due to the fact that I think that my rear shocks are dodgy, and the constant up down movement on the sway bar is causing this piston to stuff up.

Metric is the flaring that is convex right?

$90 to replace new huh...........

Any ideas's how much it would cost to kit?

thanks

shobbz
 
Hi Folks

My brand new compensator valve arrived in my mailbox yesterday. $99 bucks including GST, in pristine condition in blue Peugeot Original Equipment box. Thank's Dave at French Connection for amazingly fast service. Ordered Friday afternoon. In Tassie Tuesday morning. Who says parts for old Pugs are hard to get and cost big $$$$$$$ ?

Now the fun of fitting it..... (may as well do a full system flush while I'm at it, and replace the rear pads which arrived with the valve).
 
Any idea if u can get a kit for these?

Can these fail and not leak?

just wondering.

I agree parts can be found, just have to know where to look.

shobbz
 
Shobbz,

At $99 for a new one, I wouldn't be bothering with a kit. Any money you save by getting a kit would be spent on the extra labour involved, and at the end of the day the result would be inferior. 2_cents 2_cents

Save your pennys for a new one - roughly the same price as a night on the town with your mates. a_drink
 
I have become a fan diy kit jobs. Provided the metal casings ans such are in good condition they are often pretty good.

I do the work myself, I try to save the money that way.

Although after having a look at mine yesterday, it has seen better days:).

Wallet may be lighter in the near future.

Btw frogs4ever, were you having any rear brake problems before u discovered the leak?

Btw, the pug has sapped up much of my 'on the town ' money. The carton is my friend atm:)

thanks

shobbz
 
Shobbz:

Btw frogs4ever, were you having any rear brake problems before u discovered the leak?
Click to expand...
No particular problems which I could deffinitely attribute to the leak.

I've always felt that the brake bias was too much in favour of the front, which leads to the front wheels locking before the rears in emergency braking. This worries me because locked front wheels results in no steering. I would rather have the rears lock before the front, or a perfect 50/50 ballance. However a simple adjustment of the compensator mechanism probably would have cured this, but I never got around to it. I doubt whether the leak had anything much to do with brake bias issue, since the amount of fluid being lost was probably not enough to account for this. It is more of a weap than a leak.

I'm very happy with my brakes, except for the bias issue, and a squeel from recently fitted new front pads.
 
Having owned my 504 for 31 yrs and 500,000kms and changed the comp valve twice in that time. I can tell you that there are no kits for these valves. Not in Oz.

My last one was from the club member that bored them out and changed the seals to ones that were/are readily available. He lives/lived in Croyden Park. I've forgotten his name because I changed it about a dozen yrs ago now.
 
I've always wondered if the comp valve was on the way out in my 505 GR. My rear brakes always lock up before the front when doing an emergency brake. I always thought this wasn't normal as the other (rather ordinary) cars I've attempted this in would lock the front wheels (unless they had ABS so you couldn't really tell). I've also noticed I get more brake dust on my rear wheels than front.

But I never though before that having it biased towards the rear would allow me more steering ability. Geesh I'm dumb mallet
 
nJm:
I've always wondered if the comp valve was on the way out in my 505 GR. My rear brakes always lock up before the front........

But I never though before that having it biased towards the rear would allow me more steering ability. Geesh I'm dumb mallet
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Bias to the front or rear does not necessarily indicate failure. That is often just a simple compensator adjustment issue.

Your workshop manual will tell you how to reach a standard one-size-fits-all adjustment, but you might then like to customise it to suit your tastes once you have learnt how the adjustment is done. If you don't have and cant afford a workshop manual, let me know, and I'll post here the relevent section from mine.

By the way, brake dust is not a reliable indicator of bias. Wheel locking is.
 
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