separating pedal rod from booster drum

[Sven]

After some information from the guys at the opel junkyard, aparently a kadett D brake booster is identical to mantas... lucky me...my girlfriends father has just one one of those for scrap.

I got it off and really.. it is identical... except for one little thing.. the rod that connects to the pedal is a couple of times longer than mantas.

my question is simple, can this rod be separated from the drum in any way... or is cut & weld my only option?

Thank you.

[GTJIM]

I think the two rods will be interchangable but you will have to seperate the two halves of the booster to get them out.

I suggest you try with the old broken original one. The two halves should twist apart at the join around the centre. Just be careful that the rubber inside does not get torn in the process. When putting the replacement one back together just lubricate the edge of the rubber with a bit of brake fluid.
HTH

[Sven]

So the drum can actually be opened... i allways thought it was welded shut and the slots round the middle just some factory asembly scars... since everyone says they can't be repaired.... I should have some fun trying to get that open... but its good news if i don't have to cut anything.
Thanks!

[Paul]

The booster can be disassembled. However, I would not advise it for the average shade tree mechanic with the average tools.

The shells are crimped together, actually more like a tab in a slot, with a crimped lock. There is a big spring inside the shells. It takes 75 pounds or so to keep the spring compressed. So, once the keeper locks are bent out of the way, one shell half is rotated a few degrees to remove the tab from the slot. Then the spring pressure is released.

I worked at a automotive parts remanufactureer back in the early 80s. We had several fixtures for breaking these apart. We used a fixture mounted to a table that located on the master cylinder studs with a hole for the push rod to dangle through and a 3 inch diameter, long stroke air cylinder to keep the shells compressed. We had a special tool to un-do the crimps and another special wrench-type tool to rotate the upper shell. We had flow controls on the air cylinder so that as the air pressure was released, the cylinder retracted slowly, safely releaseing the spring energy. To re-assemble, we had similar equipment on the assembly lines.

Moral of the story... don't try to open it up with just a hammer and screw driver, or we'll be reading a new thread by you titled "How I Broke My Jaw"

HTH

[Sven]

Originally Posted by Paul don't try to open it up with just a hammer and screw driver

allready have... won't budge.

So i have to bend something before i try to rotate one side? thing is i have no other choice but to do it myself... and i lack even some basic tools, i'll take care of my jaw later, just want to get this thing apart first... will hold the spring down with a car jack and will have to improvise some kind of stand to fix it in.... i don't know... running out of ideas...

Thanks for you info..

[BQS4]

Does Croatia have a "911" system??????

[Sven]

ya, except its not 911 but 92
won't need that, if it actually opens and hits me, i'll be so happy i opened it that i won't feel the pain.

[Sven]

a tab in a slot, with a crimped lock.

So what exactly is this crimped lock? the slots look like they should just rotate slide open.. but they don't... i can't make a sharp picture up close, but i highlighted one shell red, the other green... could you please tell me by what number is the part that should be bent marked? i've been bashing it for hours, but shows no signs of movement...

[GTJIM]

I'll have a good look at my GT booster tomorrow and see what it looks like.

Just woke up and will go to my shed 8kms away today - the sun is shining!

[Sven]

*bump!*
i am desperate

[Paul]

Sven,

I went a checked my Manta A today. You are right there are no crimps that are usually present on most GM and Ford boosters. The special tool I spoke of was a home made wrench with a 4 or 5 foot long handle, 1.5 meters. I don't see how a hammer could seperate the halves. I'm sure the spring pressure inside will make it harder to seperate the 2 halves if you don't have something to clamp them.

Sorry I can't be of more help, but we never actually rebuilt any Opel boosters back then. Mostly we just did GM, Ford and Chrysler, but in big volume, about 300 per day!

[GTJIM]

Spent the weekend in bed with some deadful virus (NO - not my best Lady!).
I am about to stumble off to work tonight so will go past the workshop on the way home for a little investigation. The worst of the illness seems to have passed....

[Sven]

So no clamps! great... hammer won't do it then... i'll take it to a garage as soon as they come back from vacation, boy will they not be happy to see me bring that in
your help is greately apretiated.

@GTJIM: please don't go anywhere if you're ill!! Its not that important, i am just a kid who is impatient to get his brakes fixed before the (legal!) street racing season ends.

i should probably have to open only the kadett booster, the old manta i can cut open.. its broken anyway, just need the rod.

[GTJIM]

Had to go to work tonight anyway ( no more sick leave left! ) and the shed is on the way home so I called in - still coughing a bit but the fever has gone.

The two halves of the Opel booster definately come apart. The outer shell has a ring of pressed indentations around its edge and the inner half has a set of notches. When in use the notches have been turned away from the indentations so the un-notched metal edge locates under the indentaion to hold the halves together. Rotating the two halves so the indentations line up with the notches will allow the two halves to come apart.

If you look down the ring around the middle of the booster - with a torch - you will see the notches in between the indentations and all will become clear and understood.

HTH! (cough! cough!)