front caliper/year replacement/interchange specifics?

I don't know what the better manuals tell you, but here's what I do when working on calipers.

Before even trying at all to get the pistons out of the calipers, I push them all the way in, then go to work on the cylinders to remove ALL the crap and corrosion on the outer parts of the walls that will make them stick.

If you try to get them out first hoping they'll come out easily, that can be a big mistake.

On the lip and surfaces near the lip I use a sharp scraper or small knife, and further in I use little pieces of small very fine sandpaper and wd40 or plain oil.

I'm careful not to put any nicks or scratches deep in the cylinder where the rubber seal has to do it's work, but on the outer parts I don't worry about it too much.

Once I am satisfied I've gotten as much of the bore cleaned out as is necessary, the piston usually just slides out with no effort - I usually don't even need to hook it back to air or a brake line to pump it out.

If the piston sticks - even a little - on the way out, I push it back it, see what made it stick, and clean it a little more.

Once out, I clean up the rest of it, throw away the old rubber seal, and clean out the piston groove 100%. I'm not too fussy with the piston surfaces, just clean them all up - it's the new seal that contacts the cylinder and does the work, so the cylinder walls have to polished smooth and perfectly clean, and fairly free of nicks, scratches and wear lines.

Reply to
Oldbie
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. . . .

of course I meant on the piston here - I was watching the Daytona 500 on the tube, and thinking "piston rings" instead of thinking what I was typing. . . .

. . . and of course I meant cylinder groove here, and the piston must be smooth - the cylinder's a "don't care so much" since it's got the rubber seal. It can actually be fairly corroded, especially around the top half, and still work perfectly.

duh !

Reply to
Oldbie

my 71 ghia (VIN 141293014) has 'frozen solid' pistons in both front calipers. the calipers on it (assumed to be original) are 'single pin@the pads' type, and are also 'single bleeder per caliper' type. I see numerous replacement caliper types available, supposedly the correct part number, but will they 'fit' my spindle? (bolt centers etc the same?) does a correct part number 'infer' correct bolt centers for my spindle, and therefor a 'correct fit' "automatically"? anything else I should be concerned with?

some of the new ones available are 2 pin type (my 1 pin pads are still good) and come with and without new pads....some of those come with 1 or 2 bleeders per caliper...

educational comments certainly welcome :-) thanks

Reply to
bill yohler

Wow,..............another one I have been up against before. Well, kinda. I bought a 71 KG for the purpose o fusing the engine and disc brakes for my Beetle and ran into the same issue when installing the brakes on my Bug. While installing, I found that I had two different styles of calipers. So,...........I went to the local BUG place, and discussed this very issue with my favorite parts guy. I came away from the discussion thinking that the 2 pin caliper with double bleeders made the most sense. Here's why: It doesn;t matter which side you install the ones with double bleeders and the 2 pin brakes are more common. (or at least that's the way I remember it )

Hope this helps.

Remove "YOURPANTIES" to reply MUADIB®

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Reply to
MUADIB®

You have the original style of early Ghia ATe calipers with a single- pin used up thru 71.

For 72-3 VW switched to a 2-pin design that would use the same castings and pads as were used on early typ3s. This caliper also became the replacement caliper for the earlier single-pin versions.

74 Ghias got a completely different caliper made by Girling.

Later, when we started getting replacement ATe calipers from Brazil, the caliper was actually cheapened up a bit and an extra bleed valve was added so that it could be "ambidextrous" thus saving on stocking costs and eliminating the possibility of assembly errors. These calipers can be used on either side, but they lack a certain cutout on the face of the piston which helps to keep the pad wear even.

If you want, I can rebuild your original calipers for you, but the cost will be about the same as that for a new Brazilian L/R style caliper. I also have 3 of the 72-3 Ghia calipers rebuilt and on my shelf waiting for someone who needs one. Unfortunately they are all the same side (I don't remember offhand which side it is.) Email me if you're interested.

NOTE: ALL type 3 calipers have 42mm pistons; ALL Ghia calipers have

40mm pistons. They are almost impossible to tell apart without taking them apart somewhat, so that they often get installed on the wrong cars. I work on type 3s, and that's where I got all the Ghia calipers that are now on my shelf.

If you buy replacements, make SURE you get the right ones. The mounting holes and external appearance are identical. Type 3 calipers only came in the 2-pin style.

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----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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Reply to
Jim Adney

That's great info Jim..................I have to admit I have gone by gut instinct on whether or not to follow a particular direction in this , as I was doing the conversion from drum to disc with KG parts. I was evidently steered wrong and will do some more investigating at this point. I have a matching pair on the car now, I believe they are designated left and right, because when I purchased, they didn't have the "ambidexterous ones" in stock. I felt cheated at the time but had to get things moving. They work great as it sits. The only thing that I am concerned with at this time, after your input, is the face of the piston being machined properly as described in order to keep the pad wear even.................I still have the old ones and can check it though.

Cool to learn from.

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It's is not, it isn't ain't, and it's it's, not its, if you mean it is. If you don't, it's its. Then too, it's hers. It isn't her's. It isn't our's either. It's ours, and likewise yours and theirs. -- Oxford University Press, Edpress News

Reply to
MUADIB®

The Bentley manuals have all the details on this cutout and how it should be placed.

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----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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Reply to
Jim Adney

Just clean them up first without pushing them in too far, if at all then, and give it a go from there. It all kinda depends on where they've been sitting all those years - like, how worn were the pads the last time they were used.

Most if not all of the crap that prevents them from coming out is corrosion and scale on the outer part of the bore, where it's exposed to the elements, not the crap on the inside, especially that outer lip/edge.

Good god, no!

Hook 'em up one at a time to a working brake line on a master cylinder on a working car, freed up for the purpose, and just pump them out! Make sure you have something, like the C clamp used below, in place to "catch" it, so you don't blow brake fluid everywhere when it comes.

Clean it - spray a little wd40 on it - push the piston out a bit - push it back in a bit with a C clamp or something, clean it some more, repeat as necessary, and when it pops out in your hand you say "Gee - that wasn't hard at all!" - just like your wife says on saturday night

- hahaha.

To carry that analogy to a climax, work it in and out for a while, and it gets easier to slide, hahaha.

Reply to
Oldbie

thanks to all you guys, especially you "oldbie" with that clever idea and jim! yeah, I have plenty of wet sandpaper, all grits... :-)

you guys ought'a see what flowed out of the master cylinder-looked exactly like molten tar or crankcase 'sludge'...car hadn't been driven since 1987, and was poorly maintained before that...

jim, thanks for the important updates. so, the calipers we're discussing all share a 'common' bolt center to bolt center (regarding mounting to the spindle) dimension-good to hear. I appreciate your offer of sale on the one side caliper, but generally prefer obtaining brake stuff in 'matching sets' at least in 'sets of 2', 1 per side, both fronts' in this case. nothing against 'used' and/or rebuilt stuff', by the way - I'm attempting rebuilds myself (well, piston extractions first, which oldbie's tip will be a great help).

however, using the oldbie method, I'm kinda concerned the pistons may be so PROFOUNDLY stuck that trying to push them INward, with my strongest vice, will make matters go from 'super-stuck but good, and I _mean_ stuck' to the more severe "petrified stuck forever tighter than a shrink fit solid-seized NEVER-go-ANywhere EVER again" type-status....oh, well, nothing to loose ;-) at this point

think maybe I'll put on my welders gloves, try my "grip the caliper half tightly, place wood blocks in the correct areas, and SLAM the damn thing down as hard as POSSIBLE on my piece of 1.5 inch thick steel plate out on the concrete slab outdoors" hoping to jar the pistons loose first...should be exciting ;-/ (might ought'a wear my goggles, too)

by the way, jim, one could 'draw an inference' from your reply that the educated buyer would prefer the 'single bleeder, non-ambidextrous' calipers, correct? I mean in terms of their better pad-wear characteristics?

more, jim: when you said == NOTE: ALL type 3 calipers have 42mm pistons; ALL Ghia calipers have

40mm pistons. They are almost impossible to tell apart without taking them apart somewhat, so that they often get installed on the wrong cars. I work on type 3s, and that's where I got all the Ghia calipers that are now on my shelf.

If you buy replacements, make SURE you get the right ones. The mounting holes and external appearance are identical. Type 3 calipers only came in the 2-pin style. == are you saying the type 3 calipers 'will fit' and 'will work' on the

71 ghia but are 'inadvisable'? if 'inadvisable', for what reason, piston bore size? I'm seeing sellers of type 3 calipers, in some cases, saying they're correct for ghia's... and they (the type 3 calipers), in fact, seems to have at least what a major VW parts seller claims is the correct ghia part number for my application...

and we're saying the 2 pin (say, ghia-specific) single bleeder types are more desireable, 'moderinized' replacement versions of my 'one pinners', and correct for my application, then?

thanks again much :-)

Reply to
bill yohler

No, sorry. The late type 3 calipers, all the type 4 calipers, and the

914 calipers all take larger bolts on a wider bolt pattern.

It won't be enough. There's just not enough mass in the pistons for this to be effective.

You can blow them out with compressed air, which I DON'T recommend, because it's scary as hell and you take a chance of damaging something, including yourself. You can pump them out with brake fluid and the MC, or you can send them to me.

I prefer them simply because they have all the original features. I don't hear complaints from users of the modern calipers, but I don't know if they would notice the difference. Most people are pretty non-discriminating.

They will bolt in place, but I feel that this is a bad idea because it changes the F/R brake balance. Type 3 calipers on a Ghia will be 10% stronger so the fronts will lock up before the rears have reached their max braking force. Ghia calipers on a type 3 will be 10% weaker, so the rears will lock up first.

There seem to be lots of people out there selling the wrong parts. They don't know the difference and they don't care. Once they have your money they're done with you. Even some people who claim to be experts are selling 40mm calipers as type 3 calipers. I suspect that this is all the ATe of Brazil is making now, since the market for type

3 parts is absurdly small. So now this may be all you can buy for type 3s.

The situation for Ghia owners is probably better. The calipers that are being sold as fitting both are probably actually Ghia calipers. FWIW, you can tell the difference by just looking at the shape of the piston retaining plates. They are nicely illustrated in the appropriate Bentley manuals.

Yes.

Wow, LOTS of questions.... ;-)

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----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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Reply to
Jim Adney

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