1961 Volvo PV544 in Holland

[adarvasi]

Army, the 669012 plates are lock washers for the brake caliper, could the bolts be related?
The 83107 cushion goes on the front X member, see item 28 on page 27 of this link

https://www.cvi-automotive.se/upload...ues/pv_eng.pdf

Have a great Sunday

Andres

[Army]

Originally Posted by adarvasi

Army, the 669012 plates are lock washers for the brake caliper, could the bolts be related?
The 83107 cushion goes on the front X member, see item 28 on page 27 of this link

https://www.cvi-automotive.se/upload...ues/pv_eng.pdf

Have a great Sunday

Andres

Great stuff - I just need to print out the order again then I can trace the part numbers back to descriptions more easily than trying to find them in the parts book...

...I'll sort it in the end!

I forgot to ask yesterday has anyone got any tips for fitting 83107 to the cross member?

I'm going to revisit it tomorrow with a tube of KY jelly and see if that helps

[Army]

I was planning to make up some new fuel and brake pipes that run through the transmission tunnel. Before worrying about getting the flares right and finding the correct connectors I thought it was worth a look at the old ones.

I'm glad I did - the years of encrusted oily gunk have preserved them well



Made a hole in a bit of wood to hold the connector and the pipes in position so I can paint them =>





I think it is worth trying to save these bits as bending new is nearly always a chore (and there's enough bending needed up front)

[c1800]

Have you thought about using cupronickel/ cunifer? Easy to bend and the old ones may be pitted internally. Had an old steel line that looked ok burst when pressing the brake pedal hard after bleeding.

[Army]

Originally Posted by c1800

Have you thought about using cupronickel/ cunifer? Easy to bend and the old ones may be pitted internally. Had an old steel line that looked ok burst when pressing the brake pedal hard after bleeding.

It is hard to find steel lines here in Holland. Most shops sell the cunifer lengths in coils. I have tube straighteners and tube benders and even a decent flare kit but the originals look fine to me. I am aware that nothing lasts for ever...

...and I do appreciate the warning.

[Army]

...after thinking about the brake pipes some more I remembered that the brake booster is looking a bit tatty. So I went and took it to bits for painting.



At the moment the brake booster (not originally fitted to the PV I believe) is a PBR VH44





It looks in OK condition on the inside - no leaks

But

Looking at this bit jogged the memory and I remembered something else.

This booster has been fitted recently.

When I got the car the brakes were mega hard to press - I have a sneaky suspicion that the booster was connected up incorrectly to the old braking system.

The PV has a single circuit system with a T junction that feeds pressure to the front and rear drum brakes from a single piston master cylinder. (Instead of a more modern single rod double acting piston set up that includes a balancing force configuration between front and rear brake pressures)

The way this booster has been added is that the line going to the T junction has been by-passed via the booster (which in principle is fine)

The thing is I'm not sure about is if the third junction on the "booster master cylinder" is actually a bleed screw or if it is really meant to be a line to the rear brakes...

...I realise now I should have made a picture of that part of the booster - but perhaps someone here will know what I'm droning on about?

The internet suggests there are two versions of the VH44 booster one for "front wheels only" and the other "four wheel" - how can I tell for sure which one I have?

I can't find an online installation manual anywhere

[Ron Kwas]

Army;

Taking this component, which I would consider highly sensitive to contamination, to bits just because it needs paint, I would also consider questionable (I would have cleaned externally only, and painted to make it pretty)...I suggest you work at your highest level of care and cleanliness!

"...booster one for "front wheels only" and the other "four wheel" - how can I tell for sure which one I have?"
...if plumbed in series after splitter block for front and rear, then it affects fronts only, if plumbed in series right after Master Cyl it affects everything downstream, so I'd call that a "four wheel" installation.

...but the question is if Rear Brake Valve (accumulator) was left in place to reduce and limit instantaneous pressure rise to the rears...because simply installing Vacuum Assist unit drastically increases the pressure to the downstream wheel components, and therefore Brake Balance...this will not be an issue if you don't use the brakes at maximum or panic, but since no one can predict when and if brakes may be used in a panic stop, I recommend balance tests be performed so that the car's brake action wont be a complete surprise.

Wishing you successful stopping...every time!

[Army]

Originally Posted by Ron Kwas

Army;

Taking this component, which I would consider highly sensitive to contamination, to bits just because it needs paint, I would also consider questionable (I would have cleaned externally only, and painted to make it pretty)...I suggest you work at your highest level of care and cleanliness!

"...booster one for "front wheels only" and the other "four wheel" - how can I tell for sure which one I have?"
...if plumbed in series after splitter block for front and rear, then it affects fronts only, if plumbed in series right after Master Cyl it affects everything downstream, so I'd call that a "four wheel" installation.

...but the question is if Rear Brake Valve (accumulator) was left in place to reduce and limit instantaneous pressure rise to the rears...because simply installing Vacuum Assist unit drastically increases the pressure to the downstream wheel components, and therefore Brake Balance...this will not be an issue if you don't use the brakes at maximum or panic, but since no one can predict when and if brakes may be used in a panic stop, I recommend balance tests be performed so that the car's brake action wont be a complete surprise.

Wishing you successful stopping...every time!

I appreciate the concern Ron but I have no reservations about my ability to keep this component clean (even in my grotty workshop environment): I've done this kind of thing before.

#####

I don't think the original rear brake valve has been left in the system. I've just got a T junction that splits after the single piston master cylinder.

I'm assuming because there is a front disc conversion (single line system from an Amazon) that the rear brake cylinders were matched to the Amazon system. That's something else I'm going to have to check.

I'm a bit more concerned about the booster [master] cylinder - these in-line boosters have an "in" connection from the master cylinder that's operated by foot and then "out" connection(s) depending on the desired configuration. I have a suspicion that one of the connections which has a bleed screw fitted to it is meant to be for a separate rear brake line...

[Army]

I've left the URL where I found the information for others to find (referenced)



So it looks like the bleed screw is exactly what it appears to be - a bleed screw so the booster is only boosting a single line - not two like I thought was possible.

####

So question:-

In an Amazon single circuit with disc brakes I assume there isn't a balance valve for the rear line and that the rear brake cylinders match the caliper pistons (three pot) on the front - is this correct?

[Derek UK]

The bleed screw is a useful addition as there is often an air bubble trap here. There isn't one on the Girling or replacement Lockheed units. It can be done rather messily by loosening off one of the connections. The Amazon should have different size rear cylinders when a servo is added to to a non-servo car, something that's not often done. The servo in your diagram is increasing the pressure to the 5 way block in your diagram. That's 4 for the wheels and one for the brake switch. This is the same in the Amazon. The pipe goes from the MC goes across the back of the bulkhead and then forwards along the inner wing to the servo. The out line from the servo then doubles back to the distribution block. All this extra pipe can trap air as mentioned.
Rear cylinder size referenced here, right at the end. (Thanks Rob)
https://www.youtube.com/watch?v=RKPSws8LtNQ