HELP! - with 1971 411LE mechanic/shop in LA area
- 411NUT
- Posts: 38
- Joined: Mon Jun 20, 2005 9:58 am
Thanks again, Ray. After reading your last comment I began to have more serious doubts about the skills and/or integrity of the mechanic. I decided to reconnect the hose to see what would happen. Well, the car started and it ran on fast idle for a few minutes - then it dropped to a slow idle and continued to run smoothly! Seems there's nothing wrong at all!
I think I'm getting BS from that mechanic and now I'm questioning everything else they found wrong - although I don't doubt the rotted hoses and probably some other things (brakes). Can the tires be checked to see if they have a problem (flat spot) before investing in a new set and assuming that's the problem with the front-end shakes?
Pete
I think I'm getting BS from that mechanic and now I'm questioning everything else they found wrong - although I don't doubt the rotted hoses and probably some other things (brakes). Can the tires be checked to see if they have a problem (flat spot) before investing in a new set and assuming that's the problem with the front-end shakes?
Pete
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- raygreenwood
- Posts: 11906
- Joined: Wed Jan 22, 2003 12:01 am
Yes. Simply take the car to any decent tire shop that will let you watch what they are doing and have your tires balanced. What you are looking for is a visible oscillation of the tire. A wobble (side to side) at low speed generally means a bent rim ...as in bent at the center hub.
This is at like 10 rpm just by spinning the tire by hand. When spinning the tire up to balance speed.....if you saw no low speed wobble....but you see a high speed wobble, that can be balance. If balancing does not cure it...it is generally a bulge or a flat spot.
If at low speed...looking sideways at the wheel....you see an up and down oscillation...you probably have a spread spot on the rim. This is noticed more looking at the rim edge...and not so much the tire tread area. If you see no oscillation up and down at low speed but a noticable one at high speed.....its tires with flat spots.
What is most likly causing the stall at one point or another is probably a variable vacuum leak...or could even be caused by a cylinder head temperature sensor or a ambient air temp sensor being out of spec. Simple check with a volt meter. Ray
This is at like 10 rpm just by spinning the tire by hand. When spinning the tire up to balance speed.....if you saw no low speed wobble....but you see a high speed wobble, that can be balance. If balancing does not cure it...it is generally a bulge or a flat spot.
If at low speed...looking sideways at the wheel....you see an up and down oscillation...you probably have a spread spot on the rim. This is noticed more looking at the rim edge...and not so much the tire tread area. If you see no oscillation up and down at low speed but a noticable one at high speed.....its tires with flat spots.
What is most likly causing the stall at one point or another is probably a variable vacuum leak...or could even be caused by a cylinder head temperature sensor or a ambient air temp sensor being out of spec. Simple check with a volt meter. Ray
- 411NUT
- Posts: 38
- Joined: Mon Jun 20, 2005 9:58 am
Eureka! - Found a good 411 mechanic!
'Old Blue Eyes' is starting to twinkle again - and there may yet be more life in that old 1971 body! Found a good 411 mechanic in Montebello who just replaced just about the entire rotted, split and frayed fuel line (9' worth). Anyone know of the whereabouts of a master cylinder for a 1971 411LE? I hear they're harder to find than hen's teeth. Anyway, it's not critical yet and the big test (brakes and front end wobble) will come in the next few days.
Stay tuned.
Stay tuned.
- Piledriver
- Moderator
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- 411NUT
- Posts: 38
- Joined: Mon Jun 20, 2005 9:58 am
spit, glue and duct tape...
Yeah, I just found out that's the intake boot being held together by tape. Seems to be working, though - but I'm also looking for a new part. Anyone discover a good source of 411 parts? Car-Part returned some hits but I have yet to verify that they have the parts advertised.
- ubercrap
- Posts: 1394
- Joined: Sun Apr 18, 2004 8:00 pm
Re: spit, glue and duct tape...
You might try these guys:411NUT wrote:Yeah, I just found out that's the intake boot being held together by tape. Seems to be working, though - but I'm also looking for a new part. Anyone discover a good source of 411 parts? Car-Part returned some hits but I have yet to verify that they have the parts advertised.
http://www.thesamba.com/vw/classifieds/ ... ?id=327539
- raygreenwood
- Posts: 11906
- Joined: Wed Jan 22, 2003 12:01 am
There are a few options. Remove the master cylinder, disassemble and clean it. Inspect it carefully. If it has serious deep rust pits, it may be too far gone. If it has light surface rust and no crusty spots...you can lightly hone it. By that..I mean use a 3/4" bottle brush hone (about $18) ....lightly. I clamp tehcylinder in a vice and twist the brush by hand. The object is to remove little or no metal. Then...using 800 grit paper on a dowel...lap the inside of teh cylinder until te hhone marks are almost invisible. You do not actually want hone marks with a brake cylinder.
Then...either get a type 3 cylinder....or even cheaper buy a brake cylinder for an early 80's rabbit. Check around in the books. There are several that are 19mm just like the type 4.
That cylinder should run no more than $35. Toss the cylinder, pistons and springs. Use only the brass flap valves and the seals. Use 1000 grit paper toclean up your pistons with special attention to the seating areas for the brass flap valves. With careful assembly....and no real rust pits...this cylider shouldwork like new. In humid areas, bleeding the brakes every year and cleaning the guts out on the master cylinder every two years and rebuilding every three...will keep this thing working forever. Ray
Then...either get a type 3 cylinder....or even cheaper buy a brake cylinder for an early 80's rabbit. Check around in the books. There are several that are 19mm just like the type 4.
That cylinder should run no more than $35. Toss the cylinder, pistons and springs. Use only the brass flap valves and the seals. Use 1000 grit paper toclean up your pistons with special attention to the seating areas for the brass flap valves. With careful assembly....and no real rust pits...this cylider shouldwork like new. In humid areas, bleeding the brakes every year and cleaning the guts out on the master cylinder every two years and rebuilding every three...will keep this thing working forever. Ray
- 411NUT
- Posts: 38
- Joined: Mon Jun 20, 2005 9:58 am
Ray - the 411 'miracle man'!
Ray, I continue to be flabbergasted by your incredible 411 knowledge and solutions to 'impossible' car problems! I'm still waiting to hear about the master cylinder I found and see if I can get it and if it works - but now I know what to do if it doesn't - and there is hope (for 'Old Blue Eyes', my wife's cherished dream and my manhood )
Ray, if I get out of this 411 bind thanks to you, I'm gonna 'owe you one' (maybe more than one!)
Later.......
Ray, if I get out of this 411 bind thanks to you, I'm gonna 'owe you one' (maybe more than one!)
Later.......
- 411NUT
- Posts: 38
- Joined: Mon Jun 20, 2005 9:58 am
leaking master cylinder (2)
So our 411 mechanic delivered the devastating news yesterday - the recently arrived master cylinder also leaks! So now it's time for Ray's magic to work and restore at least one of the leaking master cylinders to life. By the way, Ray, what makes a master cylinder unique to the 411 (or any car)? Why can't an entire master cylinder from a 1982 VW rabbit, let's say, just be substituted? - along with calipers and any other connecting goodies. I'm sure this is an idiotic question, but hey, I'm just a stranger in the automotive paradise!?
- Piledriver
- Moderator
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- Joined: Sat Feb 16, 2002 12:01 am
Someone mentioned having issues with Prestone Synthetic brake fluid... Eating seals/causing leaks.
If memory serves me right, I have seen that a few times and not connected the dots.
If memory serves me right, I have seen that a few times and not connected the dots.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
- 411NUT
- Posts: 38
- Joined: Mon Jun 20, 2005 9:58 am
Help! - Ray
My 411 mechanic (?) tells me that he's not into rebuilding 411 master cylinders. Anyway, all the 1980s Rabbit cylinders I found have a 20.64mm bore. Do you know what year and Rabbit models have a 19mm bore? Meanwhile, I'm hiding our big kitchen knife from my wife!
- raygreenwood
- Posts: 11906
- Joined: Wed Jan 22, 2003 12:01 am
I would dump that mechanic personally. If he's not into rebuilding 411/412 cylinders...he's not a 411/412 mechanic....because new cylinders have been hard or impossible to find for about 20 years now.
I fact...YOU can rebuild the cylinder yourself for next to nothing on the kitchen table. My bet is that your mechanic does not like to rebuild 411/412 cylinders because he can't...or at least not successfully.
The gist is this: in rebuilding a cylinder...a quick inspection must be made to see if its even rebuildable. This is simple. Only two things will make it unrebuildable. (1) if there are any rust pits over about .001" deep. The object is to remove the piston and with a 360 grit or finer bottle brush hone...spend maybe 20-30 seconds at about 200 rpm with a drill cleaning up the bore. If all rust disappears....then you are good.
If small pits still appear up near the opening...you can take maybe a total of .002" out of the bore before it gets to be a problem. If another 30 seconds to a minute with the bore brush does not get you clean...the cylinder is gone. These rust pits will leak/bypass fluid when the seals pass over them and will also wear out the sealing cup.
Next...if the bore cleans up....you need to take 1000 to 1500 grit sandpaper (wet/dry), wrapped around a dowel...wet with brake fluid...and by hand twist it around back and forth in the bore to polish away the hone marks. The seals so not do well with hone marks. There wre no hone marks in the original bores. Wash with soap and water and oil it with brake fluid and set it aside
(2) Inspect the pistons that came out of it.....which are the only ones you can use. They are (a) specific to type 4 and (b) specific to cylinder brand...which will either be FAG or TEVES. You never want FAG seals or pistons in a TEVES cylinder or vica versa. You also never want the pistons out of any other car...or you will kill yourself. They are all specific.
Pull off the seals and remove the springs. The pistons can be reused a thosuand times....as long as there are no serious corrosion pits beneath the thin flat brass flap valves. If there is light corrosion but no pitting....this can be polished away with 1000 grit paper. You will use the new seals and flap valves form the other cylinder you will canabalize.
Most people do not realize this...but the pistons do not actually contact the bore. You will notice that they are about .0015-.020" smaller than the bore. The seals contact the bore. The pistons are simply the framework that supports the seals. In some cases you can also use the springs from anoth cylinder as long as they meet up to your piston and fit the little metal cup that fits inside of the seal.
You will need to go to a good parts shop and ask to see a few cylinders from rabbits. You are looking only for those with 19mm bores. A lot from the mid 80's are like this. Externally they will look similar in length to the 411/412 cylinder and havde two circuits....and holes for brake light switches. The ones I have in mind will be roughly $38-45. You will throw away everything but the seals and flap valves.
I have not tried this...but it may be possible in the case of very small pits....to etch them clean of rust with acid...and JB weld then before polishing the bore.
Do all the rest first. This is about a 2.5 hour operation. Ray
I fact...YOU can rebuild the cylinder yourself for next to nothing on the kitchen table. My bet is that your mechanic does not like to rebuild 411/412 cylinders because he can't...or at least not successfully.
The gist is this: in rebuilding a cylinder...a quick inspection must be made to see if its even rebuildable. This is simple. Only two things will make it unrebuildable. (1) if there are any rust pits over about .001" deep. The object is to remove the piston and with a 360 grit or finer bottle brush hone...spend maybe 20-30 seconds at about 200 rpm with a drill cleaning up the bore. If all rust disappears....then you are good.
If small pits still appear up near the opening...you can take maybe a total of .002" out of the bore before it gets to be a problem. If another 30 seconds to a minute with the bore brush does not get you clean...the cylinder is gone. These rust pits will leak/bypass fluid when the seals pass over them and will also wear out the sealing cup.
Next...if the bore cleans up....you need to take 1000 to 1500 grit sandpaper (wet/dry), wrapped around a dowel...wet with brake fluid...and by hand twist it around back and forth in the bore to polish away the hone marks. The seals so not do well with hone marks. There wre no hone marks in the original bores. Wash with soap and water and oil it with brake fluid and set it aside
(2) Inspect the pistons that came out of it.....which are the only ones you can use. They are (a) specific to type 4 and (b) specific to cylinder brand...which will either be FAG or TEVES. You never want FAG seals or pistons in a TEVES cylinder or vica versa. You also never want the pistons out of any other car...or you will kill yourself. They are all specific.
Pull off the seals and remove the springs. The pistons can be reused a thosuand times....as long as there are no serious corrosion pits beneath the thin flat brass flap valves. If there is light corrosion but no pitting....this can be polished away with 1000 grit paper. You will use the new seals and flap valves form the other cylinder you will canabalize.
Most people do not realize this...but the pistons do not actually contact the bore. You will notice that they are about .0015-.020" smaller than the bore. The seals contact the bore. The pistons are simply the framework that supports the seals. In some cases you can also use the springs from anoth cylinder as long as they meet up to your piston and fit the little metal cup that fits inside of the seal.
You will need to go to a good parts shop and ask to see a few cylinders from rabbits. You are looking only for those with 19mm bores. A lot from the mid 80's are like this. Externally they will look similar in length to the 411/412 cylinder and havde two circuits....and holes for brake light switches. The ones I have in mind will be roughly $38-45. You will throw away everything but the seals and flap valves.
I have not tried this...but it may be possible in the case of very small pits....to etch them clean of rust with acid...and JB weld then before polishing the bore.
Do all the rest first. This is about a 2.5 hour operation. Ray
- 411NUT
- Posts: 38
- Joined: Mon Jun 20, 2005 9:58 am
Thanks, Ray!
Thanks for those very detailed instructions on rebuilding the master cylinder. I'm trying to track down a compatible (19mm bore) master cylinder from a VW Rabbit through some on-line parts places. Stay tuned for more.........(problems, most likely).
And 'Happy New Year'!
And 'Happy New Year'!
- ubercrap
- Posts: 1394
- Joined: Sun Apr 18, 2004 8:00 pm
Re: leaking master cylinder (2)
Yes, braking components from a different vehicle can be adapted, but fabrication will be required for at least some of the parts (brackets, linkages, etc..) and finding parts that happen to fit, could take much catalog and junkyard hunting.411NUT wrote:So our 411 mechanic delivered the devastating news yesterday - the recently arrived master cylinder also leaks! So now it's time for Ray's magic to work and restore at least one of the leaking master cylinders to life. By the way, Ray, what makes a master cylinder unique to the 411 (or any car)? Why can't an entire master cylinder from a 1982 VW rabbit, let's say, just be substituted? - along with calipers and any other connecting goodies. I'm sure this is an idiotic question, but hey, I'm just a stranger in the automotive paradise!?