Technical Wheel cylinder links keep falling out of cylinder

Noticed a clunk sound coming from the driver side rear wheel. Pulled the drum off and found that the wheel cylinder link had popped out of the cylinder. I put it back in and went for a test drive. It worked fine for a bit and the noise went away but after a few mins the noise came back and link popped out again.

Any ideas what would be causing this?

 

Do you have residual pressure valves in your master or in line?

 

There are many different shaped links, and your picture doesn’t show us what kind it is. And my magic turban is having a hard time reading your mind to see what kind of brakes you have.

 

good point! 11” brakes on a ford 9”. here is the pass side for comparison

 

Sounds like something is missing.

 

Hopefully someone with a 9” will recognize that link. Looks like it might supposed to have some teeth that engage the shoe. Maybe the wrong size link or shoe?

 

Does your link look like this ?
I just looked up 75 Ltd with 11 inch braked to get a pic
There was a thread a few mounts ago on 9 , how many different parts for each model car / truck of same year 9 ,
So I think the 9 started in early 60s to 91 ish

Rock is a great Source for detail sizes and measurements

 

yes sir they do look like that

 

Not a expert on the 9 , wonder if correct wheel cylinder for correct Link for 11 shoe ? I would think the link would stay in shoe , spring would pull back after brake pressure released,
May be different cup depth blind bore hole for link to stay in bore of cup , longer one needed ?
"Link"

 

Was the link installed properly with the slots engaged with the shoes, or sideways?

 

Any chance the link isn’t “tall” enough where the notches engage the shoe to not fall through the notch in the shoe? Seems strange to me how it could get out.

 

Those look like GM wheel cylinder links. Ford links look like this.

 

It's too dark to go look now but If I can remember in the morning I have several nine inch ford rears out here with the brakes on them that I can get a photo of. It looks like the 74 F 150 Rear that I need to cut down for the back of the 48 has 11 inch brakes. That one is easy to get to.

Looking at it again, you have those front springs on the wrong side of the car. Pop those front springs off and take them to the opposite sides and install them so that the hooks go over the top rather than under.

That was a 10:45 pm 39 degrees outside trip.

 

If it is any help this is from the factory manual for 1961 Mercury which has a 9 inch axle with 11 inch brakes.

I think with the guide plate in the wrong place, it’ll sit on the narrow part of the pin and the shoes could slip off the wider part of the pin.

 

Nice clear picture here of what Mr48 Chevy has said.

https://www.ebay.co.uk/itm/391792368181

 

On your parking brake link it looks like you have two springs, one on each end, I think a spring should be on only one end.

 

What is the history of the brakes? The shoe return and park strut springs have been noted above, adding the auto adjust cable incorrectly installed. The wheel cylinder links and/or shoes may be also be incorrect. Looks like someone just threw some parts together. More info and better pictures would be helpful.

 

The springs, support, and self adjusted cable need to be in the correct placement. The support washer (the wierd shaped plate thingy) goes on first, then the self adjuster cable ring, then the springs.

 

I think he posted both sides. Regardless there should be 1 spring per side. I don't use anything else but the bar and spring.

Make sure the E brake cable isn't keeping the shoes off the anchor up top.

With every drum brake job, I would hit the shoes with my hands, rock them forward and backward. Also pull up on the adjuster to make sure the shoes weren't hung up on the backing plate.

 

Maybe, I thought the photos are of the same wheel just one front side and one rear side. could be wrong.

 

1960 Ford F-100 11”

 

To me it looks like the park brake is on, the anti rattle spring on the park brake strut is compressed. The strut should be loose in there when the park brake is released.

 

Thanks all and yes sorry I posted 2 pictures. The one picture with the link pin popped out is the passenger side. The one with the link pin positioned correctly is the drivers side.

I just purchased this car so familiarizing myself with the brakes I did not build. It looks to be built with this 11x2-1/4” style kit.
https://www.est1946.com/9-inchfordand8220policespecialand8221reardrumbrakes.aspx

There is actually no parking brake installed and hooked up to these drums. Dumb question, but I plan to install one in the near future, for the time being can I remove the parking brake spreader bar and see if the problem goes away?

 

Thank you! After taking another peek I see the order of operations when these were put back together was wrong. Also sounds like the primary spring goes on then the secondary spring last.

 

We have a winner. I don’t see “driprails” long side hook on either side…..

 

This is really odd. I looked up multiple different vendors who supply the kit that is on my car.

Their passenger side has the springs hooked over.
Their drivers side has the springs hooked under.

This is exactly how my car looks. Could it be that whoever built all of these kits assembled them incorrectly?

 

No idea why the link is dropping out; but a couple things:

Is there a difference or defect in the link pin or notch in the shoe; maybe switch some parts around and see what happens.

Could wrap a couple bunge cords around the shoes and have someone slowly apply and quickly release the brakes to see how things move.

Seems odd that the anti-rattle spring on e-brake crossbar is compressed so much.

There are no "left" or "right" springs, hooks are up on one side and down on the other.

Usually on brakes equipped with self adjusting hardware the short spring goes on last as in the OP's picture; the directions for "primary spring first" is listed in the directions for manual adjusting brakes.

 

JFYI, the primary and secondary shoes on the left pictured assembly are reversed.

I would leave the park struts installed correctly with one spring facing the primary shoe.

Now adjust the brakes by bringing the shoes tight against the drums, then back off 10 adjuster notches or teeth, which should result in about .030" shoe to drum clearance. The park strut should be free to move towards the primary shoe.

Now test drive and check for performance or issues.

 

Happy to report this was the crux of the issue. The self adjuster cable ring was BEHIND the shoe retaining washer so everything was real wobbly on the pin which after driving and braking must have been working the link pin loose.

Springs etc were repositioned correctly and brakes adjusted according to V8 Bob and we're back in business. The roadster can now return to the road safely.

Thank you gents!

 

As far as the red and yellow springs in this picture, they are the same spring, one side has to be opposite the other. The parking brake ( red spring ) will relax once the cable is hooked up and pushing the arm back a long with the shows being adjusted out. Shoes are installed wrong as stated above..