[Vwdiesel] Vac pump and rings

[travis gottschalk]

I had my vac pump on my truck go out 3 times in a month. Twice the the mechanic that "rebuilt" the truck did it and once by me. I found the older kits seem to work better. I think they were all black and new ones are gray. Either way it didn't take me long to get the rotary style. Well worth the cost and not having to drop $30 every time you lose braking power. 

With rings- I don't know much about the total seal ones but on standard ring sets you always space the rings evenly. If you have 4 rings you would put the ring gap in 1/4's for the spacing. If 3 then 1/3's. Can't really count the oil ring since it is just a wiper and oiling ring and does little to hold back compression so then the ring gaps would be 1/2's with the oiling ring between the two compression rings. It is wise to check ring gap. To do so you put each ring in the cylinder they are going to be installed in without the piston and put it past the top inch since that is where there will likely be carbon buildup and little to no wear since the rings on the piston don't make it up that high. Take a feeler gauge and measure the gap and compare specs in the repair manual. To little ring gap and when engine is warm you can expand the ring too much and damage things. Too much ring gap and you will have oil burn and blow by. You can go cheap if your ring gap is good and there isn't deep scratches to bead blast the rings and do a hone job. The hone should have hatch marks like a diamond (4 sided) with the horizontal passes going in making a 45 degree angle with the pass pulling the hone out. Then as Loren said get it clean. I do carb cleaner (if no seals are near by) or starting fluid if there is seals since that works as a cleaner but doesn't ruin seals and clean it out with a new lent free rag each pass till the rag comes out clean. If it isn't going together then spray WD-40 on there till you are ready to assemble and then do another clean job. Get a good ring compressor. I broke an oiling ring on the 1.6 because of a $2 cheaper ring compressor. I through that out and got the good one. Compress the rings after setting their positions with the oiling ring as near the bottom as possible. Tap the top of the piston with the wooden handle of a hammer or something similar. Make sure to have the rod lined up on the bottom so you don't bind or scratch the crank either. And pistons ONLY COME OUT THE TOP. Ask me how I found that out on the VW. I got it to the point on the bottom where a ring or two come out and then it bound up. I had to hammer on the thing till it broke the rings to pieces. It was getting new pistons and a bore job anyways. 

Loren- how hard is it to get the total seal rings out on an older engine where that top inch or so is smaller in diameter due to the carbon and lack of rings wearing on it. I won't be putting in rings anytime soon but I am interested in them. 

One more side note, if you are worried about to much compression then get the thickest head gasket. I would imagine that would even it out enough not to worry. Also NEVER put synthetic in there till after break in. You WILL glaze the cylinders. 
Travis G