PV brake master cylinder - Page 2

Army · Nov 20th, 2018, 09:33

A good bleed sounds like a good plan but don't forget the linkage to the pedal if that is worn then you might also get a bit of a weird uncertain feel

Derek UK · Nov 21st, 2018, 14:07

As you know the PV's drum brakes are somewhat fussy about adjustment. Quite common to have the fronts a bit grabby, causing a pull to one side. That doesn't address your pedal problem but as you have recently replaced the shoes (all wheels) they might have bedded in now and mean that readjustment is needed. Best start, but annoying, is to remove the drums and see where on the shoes the bedding in is taking place. That's for your own benefit and it gives you the opportunity to clear out any fresh dust. There might also be some spots that will benefit from a rub over with a good sharp file, especially the leading and trailing edges of the linings. Careful and close adjustment of the rears helps with handbrake adjustment after you are happy with how the wheels rotate. The odd slight scuffing not too much of a problem but it shouldn't try and stop the wheel from turning. Good adjustment helps with pedal travel. If the pedal movement is reduced when you put the handbrake on the rears need adjusting.

blueosprey90 · Apr 26th, 2022, 12:40

I don't know if my problem warrants a new thread, so I'll try to piggy back off of this old one.

Problem: '57 PV 444 very hard brake pedal. I want to change the brake fluid - at least in the master cylinder.

How to access the master cylinder? I can't really reach.

Looks to be a square cap and there is a special tool SVO 2384 - sort of a long T bar with a socket on the end. I found a reference to it being maybe a 28 mm socket, probably square ended. I was going to possibly try to weld up a tool, but my welding skills are very bad.

Looking for suggestions on how to get the cap off. After that will assess the next problem of how to suction out the fluid.

Derek UK · Apr 26th, 2022, 14:53

No suggestions but you could consider converting the cap to one with a hose fitting and a fluid bottle up on the bulkhead. I think a kit for conversion is readily available.

blueosprey90 · Apr 27th, 2022, 00:18

Bummer - when Derek is at a loss, I think I'm in trouble.

Derek UK · Apr 27th, 2022, 14:45

LOL! If you find out the socket size you need you can make up a long extension for it by filing each end to fit the square of the socket and a spanner.
B16? I think the starter is on the opposite side to the MC so there should be some space to work there.
Looking at the pictures of MC's, 28mm would seem to be unlikely . Much smaller and not metric. This is an interesting read. It might find you a new cap to get the size from or modify for a hose and fluid pot.
http://www.turbobricks.com/forums/sh...d.php?t=298278

How about a bath tap wrench?
https://www.screwfix.com/p/basin-wre...B&gclsrc=aw.ds

blueosprey90 · Apr 27th, 2022, 16:07

Oh, you're clever. I have a bath tap wrench and will give that a try.

This morning before work, I tried to test fit a couple different sockets and discovered interference with the frame. If I can get a caliper on it to measure size, I was thinking of trying to make a short wrench out of some flat stock steel.

blueosprey90 · Apr 28th, 2022, 16:32

"How about a bath tap wrench?"

Was a good idea, but didn't work. I got a good grab one time but the cap is on tight!

It might work ultimately, but I think it will be quicker just to pull the distributor and possibly the fuel line to get better access.

Derek UK · Apr 29th, 2022, 13:15

It might work in the future when the cap isn't so tight but you might have done the remote pot upgrade by then. Remove the dizzy by taking out the bolt that holds the clamp to the block. Means that the timing isn't changed when you replace it. How much does the heater fan get in your way? Is that a case of removing a few screws for removal from the bulkhead box?

blueosprey90 · Apr 30th, 2022, 10:50

I pulled the distributor cap, the #3 and #4 wires and the HV wire leading to the coil.

Then I pretty much climbed up on the bumper and went in head first. I got a short expandable wrench on the cap, and then used a long spanner as a sort of prybar between the engine block and the wrench handle. Popped it loose.

The cap measured 1" or 25.15 mm across the flat sides, and 1.191" or 30.16 mm across the corners. Off the car, I could almost get a 1 1/8" socket on it.

I suctioned out the old brake fluid in the MC. It was blackish, but not nearly as bad as I expected.

Heading out this A.M. to gravity bleed the front brakes while it is on jack stands.

Nov 20th, 2018, 09:33	#11
Army marches on his stomach Last Online: Feb 11th, 2022 03:15 Join Date: Jan 2018 Location: Somewhere in the Netherlands	A good bleed sounds like a good plan but don't forget the linkage to the pedal if that is worn then you might also get a bit of a weird uncertain feel __________________ 1961 Volvo PV544 the quick and easy in between project(!) 1981 Mercedes 300D <=> 230 diesel to petrol conversion project 1965 Series 2a Station Wagon mega build 1992 Mercedes 190E The car that works!

Apr 27th, 2022, 14:45	#16
Derek UK VOC Member Last Online: Yesterday 17:06 Join Date: Jul 2006 Location: Chatham	LOL! If you find out the socket size you need you can make up a long extension for it by filing each end to fit the square of the socket and a spanner. B16? I think the starter is on the opposite side to the MC so there should be some space to work there. Looking at the pictures of MC's, 28mm would seem to be unlikely . Much smaller and not metric. This is an interesting read. It might find you a new cap to get the size from or modify for a hose and fluid pot. http://www.turbobricks.com/forums/sh...d.php?t=298278 How about a bath tap wrench? https://www.screwfix.com/p/basin-wre...B&gclsrc=aw.ds Last edited by Derek UK; Apr 27th, 2022 at 15:24.

Nov 21st, 2018, 14:07	#12
Derek UK VOC Member Last Online: Yesterday 17:06 Join Date: Jul 2006 Location: Chatham	As you know the PV's drum brakes are somewhat fussy about adjustment. Quite common to have the fronts a bit grabby, causing a pull to one side. That doesn't address your pedal problem but as you have recently replaced the shoes (all wheels) they might have bedded in now and mean that readjustment is needed. Best start, but annoying, is to remove the drums and see where on the shoes the bedding in is taking place. That's for your own benefit and it gives you the opportunity to clear out any fresh dust. There might also be some spots that will benefit from a rub over with a good sharp file, especially the leading and trailing edges of the linings. Careful and close adjustment of the rears helps with handbrake adjustment after you are happy with how the wheels rotate. The odd slight scuffing not too much of a problem but it shouldn't try and stop the wheel from turning. Good adjustment helps with pedal travel. If the pedal movement is reduced when you put the handbrake on the rears need adjusting.

Apr 26th, 2022, 12:40	#13
blueosprey90 Master Member Last Online: Today 19:09 Join Date: May 2017 Location: New Milford, Connecticut	I don't know if my problem warrants a new thread, so I'll try to piggy back off of this old one. Problem: '57 PV 444 very hard brake pedal. I want to change the brake fluid - at least in the master cylinder. How to access the master cylinder? I can't really reach. Looks to be a square cap and there is a special tool SVO 2384 - sort of a long T bar with a socket on the end. I found a reference to it being maybe a 28 mm socket, probably square ended. I was going to possibly try to weld up a tool, but my welding skills are very bad. Looking for suggestions on how to get the cap off. After that will assess the next problem of how to suction out the fluid.

Apr 26th, 2022, 14:53	#14
Derek UK VOC Member Last Online: Yesterday 17:06 Join Date: Jul 2006 Location: Chatham	No suggestions but you could consider converting the cap to one with a hose fitting and a fluid bottle up on the bulkhead. I think a kit for conversion is readily available.

Apr 27th, 2022, 00:18	#15
blueosprey90 Master Member Last Online: Today 19:09 Join Date: May 2017 Location: New Milford, Connecticut	Bummer - when Derek is at a loss, I think I'm in trouble.

Apr 27th, 2022, 16:07	#17
blueosprey90 Master Member Last Online: Today 19:09 Join Date: May 2017 Location: New Milford, Connecticut	Oh, you're clever. I have a bath tap wrench and will give that a try. This morning before work, I tried to test fit a couple different sockets and discovered interference with the frame. If I can get a caliper on it to measure size, I was thinking of trying to make a short wrench out of some flat stock steel.

Apr 28th, 2022, 16:32	#18
blueosprey90 Master Member Last Online: Today 19:09 Join Date: May 2017 Location: New Milford, Connecticut	"How about a bath tap wrench?" Was a good idea, but didn't work. I got a good grab one time but the cap is on tight! It might work ultimately, but I think it will be quicker just to pull the distributor and possibly the fuel line to get better access.

Apr 29th, 2022, 13:15	#19
Derek UK VOC Member Last Online: Yesterday 17:06 Join Date: Jul 2006 Location: Chatham	It might work in the future when the cap isn't so tight but you might have done the remote pot upgrade by then. Remove the dizzy by taking out the bolt that holds the clamp to the block. Means that the timing isn't changed when you replace it. How much does the heater fan get in your way? Is that a case of removing a few screws for removal from the bulkhead box?

Apr 30th, 2022, 10:50	#20
blueosprey90 Master Member Last Online: Today 19:09 Join Date: May 2017 Location: New Milford, Connecticut	I pulled the distributor cap, the #3 and #4 wires and the HV wire leading to the coil. Then I pretty much climbed up on the bumper and went in head first. I got a short expandable wrench on the cap, and then used a long spanner as a sort of prybar between the engine block and the wrench handle. Popped it loose. The cap measured 1" or 25.15 mm across the flat sides, and 1.191" or 30.16 mm across the corners. Off the car, I could almost get a 1 1/8" socket on it. I suctioned out the old brake fluid in the MC. It was blackish, but not nearly as bad as I expected. Heading out this A.M. to gravity bleed the front brakes while it is on jack stands.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)