Rear brakes. Should I have these bits?

I have a 1983 1.8GTI tintop with a load proportioning valve on the rear axle but I also have some things in the rear brake pipes that look like a pressure reducer. I had my car mot'd today and it only just scraped through on the rear brakes. I stripped them down and checked everything but with the drum removed the wheel cylinder pistons don't move much but the brake pedal firms up before the pistons push out very far. The load proportioning valve is working ok. It's like there isn't enough pressure reaching the rear cylinders. After a bit of googling it seems I shouldn't have inline pressure reducers on my model as I have a proportioning valve and large wheel cylinders.
Tia!

They may be one way valves, which you should have, and on a 83 tintop gti you should only have those and the valve on the rear beam.

Ok mate, thanks. I do only have those and the valve on the back. Is there any other suggestions on why my rear brakes aren't great? Wheel cylinders are new, valve on the back appears to work ok and the guy in the mot centre said it was working fine. Only other thing is master cylinder.

Might be worth taking those one way valves apart and checking the little ball bearings (they only contain a spring and ball bearing) are seating correctly.  They are to maintain residual pressure in the rear brakes so possibly the issue..

Thanks for the help, another job to add to my ever growing list of things to do on my MK1!

Saulty said

Thanks for the help, another job to add to my ever growing list of things to do on my MK1!

The list never gets shorter, just when you think it's done BAM another one gets added to the list.

The challenge with an older but new to you car is getting it back to OEM functionality.  That is removing all the Previous Owners Screw-ups POS and you will have a Dependable Daily Driver that you can enjoy, but just Keep up with the Maintenance Items.
 

Pretty sure my 1.8 GTI doesn't have those and just the rear beam thing with a spring. Looks like you have both the early type and later type restrictors installed?

Edit: I tell a lie, mine does have those (its nearly 20 years since I restored it and that part is buried under the servo, master cylinder, expansion tank and metering head…..)

Those bits on my Cabriolet are on opposite sides of the MC....

Thanks for the tips. Early-1800 thanks for looking   .