repro proportioning valve

[Nacho-RT74]

guys what do you think about this... I'm really some urgent about this dist block. Seller told me is a good quality REPRO piece:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=320019378265&sspagename=ADME%3AB%3AAAQ%3AUS%3A1

I'm afraid on get a bad piece

[Nacho-RT74]

[bull]

It seems a little spendy to me. They have 100% feedback so I would imagine they aren't telling lies.

[Nacho-RT74]

thanks, for your opinion.
Anyway remember feedbacks are mostly posted when stuff is received, not after some time using it

spendy ?... if you think I have to pay around $130 down here for generic ones, not Mopar.

[G Force]

Is that a distibution block or a proprtioning valve 

[Ghoste]

Yeah, I think it's a distribution block.

[G Force]

Do distribution blocks go bad?  do the get clogged or rusted on the inside??

[Nacho-RT74]

dist blocks are with proportioning valve integrated on assembly on 3rd gens Oh well at least on all OEM Mopar front disc assemblies blocks I have seen ... is the lower "cilinder" located at rear of block.

yes they go bad. Inside the block there is a"piston" that makes works the light warning switch. at both ends of piston it does have O rings that obviouslly with dust, years and heat can be broken and then fluid goes through rear and front section of block. Apparently this is what is making my front deposit of master cilinder is getting emptied and filling the rear depositng, making overflow and getting air on front section.

I seriouslly have doubts is the master cilinder since is a Bendix part with just one year and a half of use... and mostly with car parked. I already replaced seals and problem is still there. I had that stuff already with just one week master cilinder mounted. Then it happened again one year later, and become more constantly since then.

[Nacho-RT74]

here is a diagram with internal parts.

Of course they can be also rusted inside, making te O rings don't work properly

[G Force]

Can an old distribution block reduce the amount of presure going to the calipers and therfore reduce braking power??

[Nacho-RT74]

Dont know... maybe if is clogged, but I think pedal could it be slightly hardened if thats the case.

But still, dunno.

[Nacho-RT74]

I got the dist block/prop valve... I have to admit IT LOOKS GREEAT AND LIKE THE ORIGINAL... now let's see if really works as how it looks

[G Force]

Great !     Keep us posted, I may want to swap mine out as well. 

Are there two differnt kinds of  propotioning valves?  One for disk brakes an one for drums ?

[Nacho-RT74]

it should be since 4 corners drums drives different brake fluid pressure than front disc cars. Only modification I have to make on the dist block I got is remove the earliers kind bracket attached... mine doesn't use bracket since is directly bolt on inner fender.

I think all drums cars use different stuff than this one. I think use the dist block and prop valve separatelly, not this integrated assembly.

[MellowCharger]

Hi How did you get on with your purchase?

I'm keen to know since I think I may need one too.

Cheers
lee

[Nacho-RT74]

Haven't had time to mount. I'll do a complete rebuilt job on that area:
-Master cilinder kit.
-Replace dist block.
-Change the booster parts fot new refinished ones with original looks to replace painted I have.

[Nacho-RT74]

Ok finally after find the last problem was really REALLY BAD adjusted the rear brakes shoes  I can say this piece works like a clock and looks EXACTLY to the original, so if you have prop valve problems or do you want upgrade from drums to disc your brakes... get this piece without doubts

here is her website
http://www.petesmusclecars.com/

I just had to remove bracket and enlarge attaching bolt holes since mine is attached directly to inner fender instead using a bracket

[Chatt69chgr]

That is a combination valve that is being reproduced by MB Brakes out of Asheville, NC.  Their retail name is something like Pirate Jack.  And their price is $75----that is----retail.  A dealer who set up an accout with them could get it cheaper and resell it like the guy on ebay did.  But you didn't get hurt on the price one bit.  But that part is not correct for a a 68-70 b-body (not sure what year car you have).  They were brass.  But I am sure it will work.  A lot of folks feel that since you can't adjust the differential pressure to the rear brakes with those (it's preset) that you are better off keeping the distribution block/switch and splicing in an adjustable proportioning valve toward the rear.  I am assuming front disc rear drum here. 

[Nacho-RT74]

mine is 74, front disc, rear drum... This what I got is exactly the same to the one my car had from factory,

I had a hard time trying to find this dist block.

[Paul G]

Natcho, was your proportioning valve leaking or bypassing internally? Did replacing it solve your problem? I am having a problem with rear wheel lock up during hard braking. From the diagram you posted, if the O-rings are bypassing internally inside the proportioning valve it would be possible to have the pressure from the front brake circuit bypassing to the rear brake circuit. That may cause greater brake force to the rear wheels than what it should be getting. Hence the rear wheel lockup. Do you think that may be possible?

[Nacho-RT74]

was bypassing.

I changed master cilinders piston seals set several times only to be sure ( just $5 every set ), but definitelly found dist block was internally bypassing. I think it can be rebuilt since they are just O RINGS on diferential piston. Juts need to remove the rear seat and remove piston to install O rings, but need a mini puller to be able to remove seat and reuse, since I'm not sure if I can find that seat. Will be done soon to get experience on that.

The bypassing problem makes the pressure will be lost, and brake fluid is interchanged between master cilinder bowls similar like broken master cilinder piston seals... that was what it happened to me. Big bowl was getting overflowed for a while small bowl was getting emptied untill I lost brakes completelly.

yes I got COMPLETE BRAKES now with new dist block/prop valve LIKE NEW .  I got another dist block ( used ) that a friend of mine will use on its car.

How does could act a bypassed dist block ? I just had the lost brakes experience. I have several doubts about locking problem ON DISTRIBUTION BLOCK FUNCTION since a bypass on sistem I think is exactly like a leak. Brake fluid have room to run on master cilinder cover, overflowing bowls... so is like a leak. If you get ONE BOWL completelly emptied, you lost all brakes.

Now MAYBE you can get locked brakes on PROPORTIONING VALVE FUNCTION ? who knows... I don't. Is an integrated block but this piece ( 3rd gens ) does have double function.

Hard braking lock up... I would think more about over adjusted rear adjusting screw... too tight maybe. Maybe emergency brake system locked. I got once the emergency brake link stuck on shoes armature

[rudyjrusa]

inline tubes makes new propos value for $95 dollars without bracket for 1974 charger

[Nacho-RT74]

hehe, already done LOOONG time ago , but good to know