The stockists in your link have the AP rebuild kit in stock. Maybe start off by rebuilding your existing unit with new seals?
Bleeding brakes
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Splat
- Posts: 469
- Joined: Thu Jun 02, 2011 5:12 am
Re: Bleeding brakes
SURELY Jon, “P” should be connected to the port-side brakes, and “S” to the starboard?
The stockists in your link have the AP rebuild kit in stock. Maybe start off by rebuilding your existing unit with new seals?
The stockists in your link have the AP rebuild kit in stock. Maybe start off by rebuilding your existing unit with new seals?
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jonclancy
- Posts: 993
- Joined: Tue Nov 01, 2011 9:30 pm
Re: Bleeding brakes
Port and Starboard - now where have I head those before??
Here’s the Skinny on AP, BTW:
Hi Jon,
AP (Automotive Products) no longer exists, and AP Racing was one of many divisions that formed the old AP before AP Racing was sold off in 2000.
The original brake division of the AP was caller AP Lockheed. This division was sold off to Shiftec 920e and they may offer this cylinder.
We hope this helps
Regards
The AP Racing team
So, now we know for sure. The AP Racing guys don’t recognise the standard MC part number at all.
Here’s the Skinny on AP, BTW:
Hi Jon,
AP (Automotive Products) no longer exists, and AP Racing was one of many divisions that formed the old AP before AP Racing was sold off in 2000.
The original brake division of the AP was caller AP Lockheed. This division was sold off to Shiftec 920e and they may offer this cylinder.
We hope this helps
Regards
The AP Racing team
So, now we know for sure. The AP Racing guys don’t recognise the standard MC part number at all.
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jonclancy
- Posts: 993
- Joined: Tue Nov 01, 2011 9:30 pm
Re: Bleeding brakes
These folks have stock at the time of writing. £495 Fedex’d to your door.
BG Developments Ltd
Waterside
Stoke Prior
Bromsgrove
Worcestershire
B60 4FD
www.bgdevelopments.co.uk
T:01527 873716
And so do these at a very similar price. Both are discounted.
Questmead Ltd, The Lodge, Meadowcroft Mill, Off Bury Road, Bamford, Rochdale OL11 4AU
Main Office Tel: +44 (0) 1706 36 39 39 | Email: Sales@questmead.co.uk
BG Developments Ltd
Waterside
Stoke Prior
Bromsgrove
Worcestershire
B60 4FD
www.bgdevelopments.co.uk
T:01527 873716
And so do these at a very similar price. Both are discounted.
Questmead Ltd, The Lodge, Meadowcroft Mill, Off Bury Road, Bamford, Rochdale OL11 4AU
Main Office Tel: +44 (0) 1706 36 39 39 | Email: Sales@questmead.co.uk
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Westfield 129
- Posts: 882
- Joined: Sat Jun 04, 2011 4:20 am
Re: Bleeding brakes
Man! This turned out to be complicated! I am happy that I had a spare .75 single master cylinder on the shelf when mine went full bypass a couple of weeks ago. Half an hour to install the new replacement and bleed the brakes. That said...
When the master bypassed all the pressure, and the pedal went to the floor, there were no brakes at all. Since it was a quick lap of the neighborhood to qualify the systems, this was handled by my hand brake, such as it is... Which brings me to the tandem master cylinder brake maters on the same shelf that my current .75" master was sitting on.
Squishy brakes are common for the 11s, and are more likely due to play in the standard Spridget wheel bearings than anything else... Or not. Perhaps a larger diameter master cylinder is needed to firm up the pedal a little? My LHD car has hanging pedals and not much room for a twin master setup, though a couple of the Spridget racer suppliers have pedal assemblies that "might" work. I may just have to install the tandem for peace of mind.
You owner/drivers in the UK have a firewall already pre punched for a pair of Girling/Lockheed master cylinders, available in remote reservoir configuration in 3/4", and the bias bar brake pedal is a Westfield option, and not very expensive. The installation is easy, especially if you have already installed a tandem master, as the front and rear brake systems are separated.
I would attach the front and rear lines to the chassis with brackets, then attach a few inches of braided teflon hose to attach the hard lines to the master cylinders. Eventually, the pictures of this installation will appear, as Jon has my last build archive of the brake installation on that car.
The cost of twin master cylinders is likely less expensive than a £500 master cylinder, though you will have a couple to a few hours of labor. Single "compact" master cylinders are relatively cheap, genuinely cheap to rebuild, and the installation is not taxing. Very straightforward, in fact. The results are better than you might imagine. If you think that the pedal pressure is too high, replace the master cylinders with a size smaller. Too squishy? One size lager, please. 'Went through this myself, selecting the braking feel and pedal travel on that last build. it's going to be 3/4" or 5/8". Dial in a lot more front brake than rear. on the bias bar. Best part is that you can put all of the master cylinder reservoirs up where you can service them without spilling brake fluid.
If you are trying to make the tandem work, the first thing I would do is install the Timken taper roller bearings, and make sure that you have the shims to properly set up the preload. The braking will be uniform, and the squishy, "Brakes?" lack of precision will be gone. Conficence will return. As for the brake feel, well... I am thinking that if you start with the wheel bearings first, you may not need to get rid of the tandem AP unit if you can get used to the feel. Seriously, though... With the cost of a tandem master cylinder being 8X the cost of some Girling/Lockheed pattern single masters, this modification becomes a no brainer if you have the time to do it. Very satisfying when you are done. Real brakes.
Jon and I had a good time in the 11, and the R5Turbo 2 that I have recently restored. I demonstrated how a proper tarmac rally suspension should work on a mid corner dip at around 30 mph, and how fast a little car can accelerate with just 1400cc and 23psi boost.
Next time, Jon will bring his driving shoes so that his feet can fit into the narrower LHD footwell, and my closely spaced pedals.
When the master bypassed all the pressure, and the pedal went to the floor, there were no brakes at all. Since it was a quick lap of the neighborhood to qualify the systems, this was handled by my hand brake, such as it is... Which brings me to the tandem master cylinder brake maters on the same shelf that my current .75" master was sitting on.
Squishy brakes are common for the 11s, and are more likely due to play in the standard Spridget wheel bearings than anything else... Or not. Perhaps a larger diameter master cylinder is needed to firm up the pedal a little? My LHD car has hanging pedals and not much room for a twin master setup, though a couple of the Spridget racer suppliers have pedal assemblies that "might" work. I may just have to install the tandem for peace of mind.
You owner/drivers in the UK have a firewall already pre punched for a pair of Girling/Lockheed master cylinders, available in remote reservoir configuration in 3/4", and the bias bar brake pedal is a Westfield option, and not very expensive. The installation is easy, especially if you have already installed a tandem master, as the front and rear brake systems are separated.
I would attach the front and rear lines to the chassis with brackets, then attach a few inches of braided teflon hose to attach the hard lines to the master cylinders. Eventually, the pictures of this installation will appear, as Jon has my last build archive of the brake installation on that car.
The cost of twin master cylinders is likely less expensive than a £500 master cylinder, though you will have a couple to a few hours of labor. Single "compact" master cylinders are relatively cheap, genuinely cheap to rebuild, and the installation is not taxing. Very straightforward, in fact. The results are better than you might imagine. If you think that the pedal pressure is too high, replace the master cylinders with a size smaller. Too squishy? One size lager, please. 'Went through this myself, selecting the braking feel and pedal travel on that last build. it's going to be 3/4" or 5/8". Dial in a lot more front brake than rear. on the bias bar. Best part is that you can put all of the master cylinder reservoirs up where you can service them without spilling brake fluid.
If you are trying to make the tandem work, the first thing I would do is install the Timken taper roller bearings, and make sure that you have the shims to properly set up the preload. The braking will be uniform, and the squishy, "Brakes?" lack of precision will be gone. Conficence will return. As for the brake feel, well... I am thinking that if you start with the wheel bearings first, you may not need to get rid of the tandem AP unit if you can get used to the feel. Seriously, though... With the cost of a tandem master cylinder being 8X the cost of some Girling/Lockheed pattern single masters, this modification becomes a no brainer if you have the time to do it. Very satisfying when you are done. Real brakes.
Jon and I had a good time in the 11, and the R5Turbo 2 that I have recently restored. I demonstrated how a proper tarmac rally suspension should work on a mid corner dip at around 30 mph, and how fast a little car can accelerate with just 1400cc and 23psi boost.
Next time, Jon will bring his driving shoes so that his feet can fit into the narrower LHD footwell, and my closely spaced pedals.
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Euan Hoosearmy
- Posts: 13
- Joined: Tue Jul 08, 2025 1:40 pm
Re: Bleeding brakes
I had a squishy pedal on the SEIW, passed MOD but never gave confidence, it felt like the pedal was constantly moving away from you...
I've swapped to a AP cylinder from Caterham and to be honest at first it didn't seem that much better, but recently the pedal has become really nice and firm without me having changed anything....
My theory is that there was air trapped in the MC somewhere and that's found its way out. I have seen some people suggest connecting a small vac pump to a filler cap with a spigot through it to reduce pressure in the reservior to encourage such bubbles out - does it work...? I have no idea.
Another vote for pressure bleeders, I have the Sealey one and it works really well on anything with a standard AP/ford reservoir cap.... however BMWs and Rovers have different caps which mean buying specific ones or messing around with the universal fit one. None of them are cheap.
I've swapped to a AP cylinder from Caterham and to be honest at first it didn't seem that much better, but recently the pedal has become really nice and firm without me having changed anything....
My theory is that there was air trapped in the MC somewhere and that's found its way out. I have seen some people suggest connecting a small vac pump to a filler cap with a spigot through it to reduce pressure in the reservior to encourage such bubbles out - does it work...? I have no idea.
Another vote for pressure bleeders, I have the Sealey one and it works really well on anything with a standard AP/ford reservoir cap.... however BMWs and Rovers have different caps which mean buying specific ones or messing around with the universal fit one. None of them are cheap.
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Westfield 129
- Posts: 882
- Joined: Sat Jun 04, 2011 4:20 am
Re: Bleeding brakes
Getting rid of squishy brakes is easy if you have the right tool. Even if you have not bench bled the master cylinder, even if you have not bench bled a tandem master cylinder.
What you need, really, is a PRESSURE BLEEDER. One with a hand pump, built in, and a large canister to hole pressure with a pressure gauge.
I use MOTIVE POWER, but there are others. The Motive Power is all of $50 here in the states, and it will save you untold hours of toil, and even save a relationship or two as YOU CAN BLEED THE BRAKES SINGLE HANDED, AND NEVER PUMP THE PEDAL until you are finished.
The pressure bleeder has a cap that fits your master cylinder. Motive Power and others have standard Euro and Girling/Lockheed type caps available (or included), as well as others including the 3" Lockheed that I happen to have on my Morgan's clutch master.
The pressure bleeder will also automatically replenish the master cylinder while you are bleeding, ensuring that those of you with small single master cylinder systems won't be emptied and then, well, you have to start again.
Using the pressure system is easy. Fill the master cylinder with fresh fluid. The bleeding process will also allow flushing the system at the same time, very quickly.
Add some fresh brake fluid to the pressure bleeder canister.
Attach the cap of the bleeder to your master cylinder.
Pump the bleeder up to 15~20 psi. The bleeder will hold that pressure for the entire bleeding process, and keep a supply of fresh fluid replenishing the level in your master cylinder.
You are now ready for bleeding the brakes, starting with the one farthest from the master cylinder. Hook up the collection bottle (no need to fill it as you can see any bubbles in the hose).
Crack open the bleed screw, and note the flow of fluid. When the air bubbles are gone, and the fluid is clear and fresh, tighten the screw and move onto the next brake.
Repeat as necessary. Clearing each brake line and caliper/wheel cylinder takes only a few seconds.
When you are finished bleeding all the brakes, you will find that you still have plenty of pressure in the bleeder, and the reservoir should still be full. Slowly remove the cap from the reservoir so not to splash any fluid and slowly release the residual pressure.
You should now have a solid brake pedal or clutch pedal, depending on which system you serviced. No other attention should be required. All air should be purged from your hydraulics. Go drive.
There is no hand pumping of those little Mityvac vacuum pumps. No pumping of brakes and yelling at the brake pedal pumper. You do not even have to stop and refill the reservoir if you use the bleeder to do that for you. And it is not an expensive tool. No down side that I can find, unless you get lonely doing this usually boring job (which now takes only a few minutes, and you did by yourself.
Having a pressure bleeder, and a set of taper wheel bearings to replace those ball bearings in the front hubs will give you confidence inspiring brakes. No longer will they feel like stepping on a dead squirrel, soft with hard bits... Been there, done that... Found the fix.
As for using a different master cylinder.. If you go to a larger diameter master cylinder, the pedal will be harder, and have a shorter travel. If the pedal pressure is too high, you can go to a smaller master cylinder and get a perhaps more progressive feel and lower pedal pressure.
Moat of my friends with Caterhams have changed their master cylinders to the larger option to get a firmer pedal.
I often use twin master cylinders and will occasionally guess wrong, and have to change out the cylinders for some that are either one size larger or smaller. Which I choose is completely subjective. I pick what makes the brakes feel best to me. I always make changes that are incremental. One size larger or smaller. No big changes. 1/16" is certainly noticeable in both pedal pressure and travel.
What you need, really, is a PRESSURE BLEEDER. One with a hand pump, built in, and a large canister to hole pressure with a pressure gauge.
I use MOTIVE POWER, but there are others. The Motive Power is all of $50 here in the states, and it will save you untold hours of toil, and even save a relationship or two as YOU CAN BLEED THE BRAKES SINGLE HANDED, AND NEVER PUMP THE PEDAL until you are finished.
The pressure bleeder has a cap that fits your master cylinder. Motive Power and others have standard Euro and Girling/Lockheed type caps available (or included), as well as others including the 3" Lockheed that I happen to have on my Morgan's clutch master.
The pressure bleeder will also automatically replenish the master cylinder while you are bleeding, ensuring that those of you with small single master cylinder systems won't be emptied and then, well, you have to start again.
Using the pressure system is easy. Fill the master cylinder with fresh fluid. The bleeding process will also allow flushing the system at the same time, very quickly.
Add some fresh brake fluid to the pressure bleeder canister.
Attach the cap of the bleeder to your master cylinder.
Pump the bleeder up to 15~20 psi. The bleeder will hold that pressure for the entire bleeding process, and keep a supply of fresh fluid replenishing the level in your master cylinder.
You are now ready for bleeding the brakes, starting with the one farthest from the master cylinder. Hook up the collection bottle (no need to fill it as you can see any bubbles in the hose).
Crack open the bleed screw, and note the flow of fluid. When the air bubbles are gone, and the fluid is clear and fresh, tighten the screw and move onto the next brake.
Repeat as necessary. Clearing each brake line and caliper/wheel cylinder takes only a few seconds.
When you are finished bleeding all the brakes, you will find that you still have plenty of pressure in the bleeder, and the reservoir should still be full. Slowly remove the cap from the reservoir so not to splash any fluid and slowly release the residual pressure.
You should now have a solid brake pedal or clutch pedal, depending on which system you serviced. No other attention should be required. All air should be purged from your hydraulics. Go drive.
There is no hand pumping of those little Mityvac vacuum pumps. No pumping of brakes and yelling at the brake pedal pumper. You do not even have to stop and refill the reservoir if you use the bleeder to do that for you. And it is not an expensive tool. No down side that I can find, unless you get lonely doing this usually boring job (which now takes only a few minutes, and you did by yourself.
Having a pressure bleeder, and a set of taper wheel bearings to replace those ball bearings in the front hubs will give you confidence inspiring brakes. No longer will they feel like stepping on a dead squirrel, soft with hard bits... Been there, done that... Found the fix.
As for using a different master cylinder.. If you go to a larger diameter master cylinder, the pedal will be harder, and have a shorter travel. If the pedal pressure is too high, you can go to a smaller master cylinder and get a perhaps more progressive feel and lower pedal pressure.
Moat of my friends with Caterhams have changed their master cylinders to the larger option to get a firmer pedal.
I often use twin master cylinders and will occasionally guess wrong, and have to change out the cylinders for some that are either one size larger or smaller. Which I choose is completely subjective. I pick what makes the brakes feel best to me. I always make changes that are incremental. One size larger or smaller. No big changes. 1/16" is certainly noticeable in both pedal pressure and travel.