hi folks does any one know where i can get a master cylinder for my 73 412 le as its now leaking eithere a rebuild kit or a new unit
cheers peeps
master cylinder
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Jan Peter de geus
- Posts: 76
- Joined: Fri Jun 06, 2003 2:56 am
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raygreenwood
- Posts: 11910
- Joined: Wed Jan 22, 2003 12:01 am
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raygreenwood
- Posts: 11910
- Joined: Wed Jan 22, 2003 12:01 am
No I don't. This is one of the hundreds of things I need to photograph and post. If the weather starts to clear up around here...I can get some done in the nxt two weeks.
The trick of this set-up....is that you need to "mimic" the power brake hardware set-up. What this entails.....is to remove the pedal cluster under the dash and steering column. That in itself is not bad.
From the inside of the trunk just below and to the left of the reservoir(toward the passenger seat)...you will see a stamped metal boss. That boss...is where the pushrod from the brake booster would go through.
Take a good bi-metal hole saw the diameter of the round flange on the bus brake cylinder...and drill this boss through the fire-wall.
You then need to fabricate from 1/4" steel plate...an identical backing flange for the flange on the brake master cylinder. Drill, tap and screw in two studs in the same bolt pattern as the master cylinder. Transfer that pattern to the hole you drilled on the firewall. Drill two 8mm holes. Install the plate on the inside under the dash with the studs sticking through into the trunk. With lockwashers and nuts....install the master cylinder.
That part will now be done. You can do the reservoir one of two ways. The ideal way....is to get the stock bus low profile reservoir that plugs into the grommets on top of the master cylinder. Watch you clearance height when the bonnet is closed. Or.....disconnect the strap on the stock master cylinder...and turn it around so the nipples are in teh trunk and run hoses.
Of course if you have a manual tranny and hydraulic clutch like I do....this now gives you a problem in routing the supply to the clutch master.
Next.....remove the old steel lines. Drill two holes in teh sheet metal near the fire wall inside of the trunk. A vertical drop to the brake union and a small amount of bending on som new metric lines and it is simple to hook up the front circuit. The union "tee" is bolted to the firewall down underneath near the gas tank. The rear circuit requires a doube female union....also simple.
The real part of work is this....When you push on your brake pedal...the push rod...pushes back toward you. So what you need to fabricate.....is a short "A" frame bracket on top of the pedal cluster. It will need to have a piece of axle inserted across it....just below teh hole in the firewall.
I made mine with a 1/2 shaft with snap rings on each outer end. I then had a disc....of 1/2" thick steel cut out with a carbide hole saw. It is about 3" in diameter. I had a 1" hole milled in the center. I had a steel bushing tube...1" od and 5/8" ID welded into the center hole. I pressed in a 5/8" OD....1/2" ID bronze bushing tube.
Here was the calculation and experiment. This took and afternoon by the way. You need to measure the needed full stroke of teh master cylinder....and measure the desired stroke of the foot pedal. By this...I mean....if you only want the pedal to stroke halfway to the floor....to reach full master cylinder stroke......measure the amount of movement of the pushrod...created by the desired stroke of the pedal
The closer to the center of the steel disc....you place the pin...that links the pedal pull rod.....the higher the ratio on rotation. Likewise....the farthr from the center you place the actual mater cylinder pushrod...mounted 180* away from the pedal pull rod pin....the higher the degree of stroke...per each degree of rotation of that disc.
You can drill several holes at varying distancesfrom center point on the disc.....to make a very adjustable stroke.
I used 10mm diameter shoulder bolts (grade 12.9)...with heim/ball joints. I used tool steel bar for the linkage. Its heavy overkill...but its brakes...so I wantit that way.
The bushing in the center of the disc is welded such that it is about 1/2" off center from the hole in the firewall...so that I do not have to have "fork" shaped rod ends like on the stock pushrod. They are just ball joint rod ends and the shoulder bolts are on one side of the disc.
By the way..I have not driven on this yet...but the pedal is awesome. Especially since this is a 21.5mm master cylinder (if I recall correctly)....and is slightly longer stroke than the stock 411/412. This means it has volume to spare for future brake upgrades. New cylinders and recbuild kits are easy to get....and it is out from under the dash.
In the quest to keep my 412 original...there are few things I like to change....but practical is practical. At some point we will not be able to get cylinders. At that point...these cars will just be museum pieces. Ray
The trick of this set-up....is that you need to "mimic" the power brake hardware set-up. What this entails.....is to remove the pedal cluster under the dash and steering column. That in itself is not bad.
From the inside of the trunk just below and to the left of the reservoir(toward the passenger seat)...you will see a stamped metal boss. That boss...is where the pushrod from the brake booster would go through.
Take a good bi-metal hole saw the diameter of the round flange on the bus brake cylinder...and drill this boss through the fire-wall.
You then need to fabricate from 1/4" steel plate...an identical backing flange for the flange on the brake master cylinder. Drill, tap and screw in two studs in the same bolt pattern as the master cylinder. Transfer that pattern to the hole you drilled on the firewall. Drill two 8mm holes. Install the plate on the inside under the dash with the studs sticking through into the trunk. With lockwashers and nuts....install the master cylinder.
That part will now be done. You can do the reservoir one of two ways. The ideal way....is to get the stock bus low profile reservoir that plugs into the grommets on top of the master cylinder. Watch you clearance height when the bonnet is closed. Or.....disconnect the strap on the stock master cylinder...and turn it around so the nipples are in teh trunk and run hoses.
Of course if you have a manual tranny and hydraulic clutch like I do....this now gives you a problem in routing the supply to the clutch master.
Next.....remove the old steel lines. Drill two holes in teh sheet metal near the fire wall inside of the trunk. A vertical drop to the brake union and a small amount of bending on som new metric lines and it is simple to hook up the front circuit. The union "tee" is bolted to the firewall down underneath near the gas tank. The rear circuit requires a doube female union....also simple.
The real part of work is this....When you push on your brake pedal...the push rod...pushes back toward you. So what you need to fabricate.....is a short "A" frame bracket on top of the pedal cluster. It will need to have a piece of axle inserted across it....just below teh hole in the firewall.
I made mine with a 1/2 shaft with snap rings on each outer end. I then had a disc....of 1/2" thick steel cut out with a carbide hole saw. It is about 3" in diameter. I had a 1" hole milled in the center. I had a steel bushing tube...1" od and 5/8" ID welded into the center hole. I pressed in a 5/8" OD....1/2" ID bronze bushing tube.
Here was the calculation and experiment. This took and afternoon by the way. You need to measure the needed full stroke of teh master cylinder....and measure the desired stroke of the foot pedal. By this...I mean....if you only want the pedal to stroke halfway to the floor....to reach full master cylinder stroke......measure the amount of movement of the pushrod...created by the desired stroke of the pedal
The closer to the center of the steel disc....you place the pin...that links the pedal pull rod.....the higher the ratio on rotation. Likewise....the farthr from the center you place the actual mater cylinder pushrod...mounted 180* away from the pedal pull rod pin....the higher the degree of stroke...per each degree of rotation of that disc.
You can drill several holes at varying distancesfrom center point on the disc.....to make a very adjustable stroke.
I used 10mm diameter shoulder bolts (grade 12.9)...with heim/ball joints. I used tool steel bar for the linkage. Its heavy overkill...but its brakes...so I wantit that way.
The bushing in the center of the disc is welded such that it is about 1/2" off center from the hole in the firewall...so that I do not have to have "fork" shaped rod ends like on the stock pushrod. They are just ball joint rod ends and the shoulder bolts are on one side of the disc.
By the way..I have not driven on this yet...but the pedal is awesome. Especially since this is a 21.5mm master cylinder (if I recall correctly)....and is slightly longer stroke than the stock 411/412. This means it has volume to spare for future brake upgrades. New cylinders and recbuild kits are easy to get....and it is out from under the dash.
In the quest to keep my 412 original...there are few things I like to change....but practical is practical. At some point we will not be able to get cylinders. At that point...these cars will just be museum pieces. Ray
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wildthings
- Posts: 1171
- Joined: Thu Jun 03, 2004 12:42 am
Check here, they list several different brands of master cylinders for a Type 4.
http://www.autopartsgiant.com/
Note: Their website doesn't alway work right and they do not alway have what they list.
http://www.autopartsgiant.com/
Note: Their website doesn't alway work right and they do not alway have what they list.
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raygreenwood
- Posts: 11910
- Joined: Wed Jan 22, 2003 12:01 am
Its interesting that they have the correct picture.
Also...wagner never manufactured this cylinder or kits for it (at least available on this continent). Its interesting that they list wagner rebuilds. I have never even seen a wagner reman and there were only two companies that ever rebuilt this cylinder to my knowledge. That would be Teves and recently Lucas (under ownership of TRW...before the whole thing was swallowed by Kelsey hayes).
It worries me because in production there were only two makes of this cylinder. That would be FAG and Teves. Their pistons are not interchangeable. Neither are their seals. Doing so produces a semi-functional (if not completely non-functional cylinder). It has to do with exact placement of replenishment ports in refernce to cylinder borings....and proper seal to piston fit.
This place could be the gold mine....or it could simply be yet another place identical to hundreds of other places....that when you finally order your cylinder...ends up shipping you a cylinder for a type 3. In this country....forever....when you go to a generic parts house cain to get brake and suspension parts for the 411/412....they say "sure we have that.....heres your part #". It comes in....and its type 3 or type 1. And...in teh books....they list the same part # for type 3 and 4.
I usually get the question when I am on a ball joint search....."upper or lower"?. "Uh...dude....it only has lower ball joints." "Nope...book says it has upper and lower....book is never wrong".
Like I said. It is interesting that they have the correct picture. Its worth checking out. There may be hope.
Also bear in mind that quality is critical. Fully 70% of all type 4 cylinders are NOT rebuildable. This is because their location under the dash causes excessive rust at the outer end of the bore due to humidity build-up. The only way to salvage these....is to re-bore....NOT hone....and then install oversize pistons (never made).
Of course..Wagner has that capability ...and maybe they have started doing that. Or maybe they are chrome-plating the bore (doubtful).
But if you buy one...and you pull the outer piston and clip out...and see any pits in the bore what-soever....its junk. Also....if it has hone marks....its Junk. The seals will last maybe 30K miles...if they seal right at all.
New master cylinders have polished/lapped bores....not hone marks. These are not "steel" rings we are breaking in. The proper way is to cut slow...with 320-380 grit stones...and then "lap" with a lapping bar and lapping compound. Wash clean...and slip in the pistons.
I have two 5 gallon buckets of 411/412 cores. At some point I may try my hand at stainless liners. But another bugaboo is getting proper seals and compensation port valves (the little brass flaps). Again....Teves parts work with teves...and Fag with Fag.
You can use the seals and flap valves ONLY..from a Teves type 3 master cylinder kit to rebuild a Teves type 4 master cylinder as long as there is no corrosion on piston faces where the brass flap valves seat...your pistons will be reusable. The seals and flap valves ONLY from a type 3 FAG cylinder...will rebuild an FAG type 4 cylinder.
If you try to swap type 3 pistons into a type 4 cylinder (or vica-versa...or from or to any other cylinder for that matter)..you are screwed.
I actually have access to several NOS type 4 master cylinders. Two manual...one power...about a mile from my house. This place is a Teves dealer. He says....that as long as a Teves vendor has an operatin part #...he can get you a factory rebuild cylinder in a few weeks. The cost...is in teh $150-190 range....which has been the case since the mid 80's.
The low cost on that parts site.... $26 something.....also leads me to believe that possibly these are not type 4 parts. The cores are worth more than that.
Anyway...all of these issues are some of the reasons I just decided to look for a better more reasonable cylinder alternative. If I could drop into any foreign parts store and know that I could order a master cylinder at will of the proper type 4 part #...I would never dream of using anything else. Ray
Also...wagner never manufactured this cylinder or kits for it (at least available on this continent). Its interesting that they list wagner rebuilds. I have never even seen a wagner reman and there were only two companies that ever rebuilt this cylinder to my knowledge. That would be Teves and recently Lucas (under ownership of TRW...before the whole thing was swallowed by Kelsey hayes).
It worries me because in production there were only two makes of this cylinder. That would be FAG and Teves. Their pistons are not interchangeable. Neither are their seals. Doing so produces a semi-functional (if not completely non-functional cylinder). It has to do with exact placement of replenishment ports in refernce to cylinder borings....and proper seal to piston fit.
This place could be the gold mine....or it could simply be yet another place identical to hundreds of other places....that when you finally order your cylinder...ends up shipping you a cylinder for a type 3. In this country....forever....when you go to a generic parts house cain to get brake and suspension parts for the 411/412....they say "sure we have that.....heres your part #". It comes in....and its type 3 or type 1. And...in teh books....they list the same part # for type 3 and 4.
I usually get the question when I am on a ball joint search....."upper or lower"?. "Uh...dude....it only has lower ball joints." "Nope...book says it has upper and lower....book is never wrong".
Like I said. It is interesting that they have the correct picture. Its worth checking out. There may be hope.
Also bear in mind that quality is critical. Fully 70% of all type 4 cylinders are NOT rebuildable. This is because their location under the dash causes excessive rust at the outer end of the bore due to humidity build-up. The only way to salvage these....is to re-bore....NOT hone....and then install oversize pistons (never made).
Of course..Wagner has that capability ...and maybe they have started doing that. Or maybe they are chrome-plating the bore (doubtful).
But if you buy one...and you pull the outer piston and clip out...and see any pits in the bore what-soever....its junk. Also....if it has hone marks....its Junk. The seals will last maybe 30K miles...if they seal right at all.
New master cylinders have polished/lapped bores....not hone marks. These are not "steel" rings we are breaking in. The proper way is to cut slow...with 320-380 grit stones...and then "lap" with a lapping bar and lapping compound. Wash clean...and slip in the pistons.
I have two 5 gallon buckets of 411/412 cores. At some point I may try my hand at stainless liners. But another bugaboo is getting proper seals and compensation port valves (the little brass flaps). Again....Teves parts work with teves...and Fag with Fag.
You can use the seals and flap valves ONLY..from a Teves type 3 master cylinder kit to rebuild a Teves type 4 master cylinder as long as there is no corrosion on piston faces where the brass flap valves seat...your pistons will be reusable. The seals and flap valves ONLY from a type 3 FAG cylinder...will rebuild an FAG type 4 cylinder.
If you try to swap type 3 pistons into a type 4 cylinder (or vica-versa...or from or to any other cylinder for that matter)..you are screwed.
I actually have access to several NOS type 4 master cylinders. Two manual...one power...about a mile from my house. This place is a Teves dealer. He says....that as long as a Teves vendor has an operatin part #...he can get you a factory rebuild cylinder in a few weeks. The cost...is in teh $150-190 range....which has been the case since the mid 80's.
The low cost on that parts site.... $26 something.....also leads me to believe that possibly these are not type 4 parts. The cores are worth more than that.
Anyway...all of these issues are some of the reasons I just decided to look for a better more reasonable cylinder alternative. If I could drop into any foreign parts store and know that I could order a master cylinder at will of the proper type 4 part #...I would never dream of using anything else. Ray
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plumcrazee
- Posts: 128
- Joined: Mon Jan 02, 2006 10:18 am
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raygreenwood
- Posts: 11910
- Joined: Wed Jan 22, 2003 12:01 am
You guys are on the same mind track that I have been through. The problem with doing that.....is that the bus master cylinder and all type 1-3 cylinders have mounting EARS...not side tabs like the type 4.I installed a type 33 master cylinder first...under the dash. I had to weld on a bracket that is the same pattern as the mounting ears, and cut a slot in the pedal bracket so that the type cylinder would sit close enough to the pedal bracket to line up with the pushrod.
This would have worked well....except that good type 3 cylinders are almost as hard to find as a type 4 cylinder. So...I tried a late rabbit cylinder... same stroke and diameter. But...it had different compensation port in the pistons...and it caused replenishment problems. No rear brakes for a minute fter a hard stop
.This mod was as much work as moving the cylinder would be. Either way the pedal cluster needs to come out.
Which reminds me of a warning....I need to give. When swapping brake masters....it is not JUST the same stroke length and volume that is important. If the small drillings or holes in the pistons.... the ones under the brass flap valves.....are not equal to or larger than what was original....in both number and diameter.....you will have serious and dangerous problems. This is why I went to a bus cylinder. It was larger volume all the way around....no problems.
Super beetle cylinders will not work....though the stroke and volume suggests at a glance that they might . Rabbit cylinders will not work either...thrpough stroke, piston diameter and volume suggest they should. This should have been apparent.....if I had inspected teh compensation/replenishment ports.
The ports are smaller...because the rabbit....has a single piston caliper up front and smaller diameter (17mm) brake cylinders in the back. It does not move as much fluid in one stroke. Same issues with all type 1.
Type 3 cylinders work...because internally the piston volume and stroke....and compensation ports are the same as type 4...as are the calipers and rear wheel cylinders.
But....BIG WARNING. The pistons of the type 3 cylinder have differnt spacing between piston heads than the type 4 cylinder. So If you installed type 3 pistons in a type 4 cylinder....the piston heads will block the replenishment ports...and your brakes will fail 100%...because they cannot draw in fresh fluid.
Oh...by the way.....the seals from a brazilian version of the Teves cylinder for late rabbit with the long cylinder and 19mm pistons...will also work for rebuiling type 4 cylinders. Ray
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Wally
- Posts: 4567
- Joined: Mon Oct 28, 2002 12:01 am
BTW BTWraygreenwood wrote: Oh...by the way.....the seals from a brazilian version of the Teves cylinder for late rabbit with the long cylinder and 19mm pistons...will also work for rebuiling type 4 cylinders. Ray
- and I have written this earlier - the first part of a type 1 master is eaxctly the same as the first part of the type 4 master. The deeper part is different in length tho and cannot be used. Just compare them side to side and you'll see 
So if your type 4 master housing is nice and smooth on the inside, you can swap these out easily. Since the rubber seals are usually causing the leak and the ones closest to the rod are the worst, you have a very good chance this will cure your leak.
It did with mine and have been driving my type1/ type 4 hybrid MC for a few thousand miles now without a drop
T4T: 2,4ltr Type 4 Turbo engine, 10.58 1/4 mi in a streetlegal 1303
"Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
"Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
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raygreenwood
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plumcrazee
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