Tips or Tricks for removing rusty pipes from manifolds - PeachParts Mercedes-Benz Forum

todds · #1 04-13-2009, 10:25 AM

I'm re-doing the induction system on the ol' m180 and somehow got lucky enough to get all the rusty manifold bolts off. So the intake/exhaust is free from the engine and I can slide it out, but it is not releasing from the two exhaust pipes. They appear to be rusted to the inside of the manifolds. I tried wedging a small breaker bar in between the flanges and hitting it gingerly with a small sledge but it didn't want to budge. I also hit it with a bunch of PB-Blaster. Anyone have any more ideas?

I could go at it with a pickle fork and really whale on it, but I'm afraid of either wrecking the flanges, cracking the manifolds or forcing the exhaust pipe flange back over the "bump" never to return.

bwostosh · #2 04-13-2009, 11:20 AM

Ah, the trials and joys of old car repair, Been there.
Get the intake manifold out.
Leave the exhaust sort-of attached
Release the exhaust system rubber hangers at rear.
Wiggle it a lot to break the rust connection
Bang only on the head pipes. never the manifold.
I use the small sledge

Keep at it, they will release,
You may need to get new head pipes
(the aftermarket "Anza" brand is fairly cheap).

todds · #3 04-13-2009, 11:36 AM

Would heat help or hurt in this case? Again I suppose I run the risk of cracking my manifolds, although I do have a backup pair... Perhaps I can wrap the pipes with cold wet/icy towels then feather the manifolds with a torch? I'd really like to try to save the pipe if I could b/c it's in otherwise great shape.

I'm not sure how I can seperate the intake in-place, I suppose from underneath I can wriggle up in there somehow. I think you're right in that this might be the most gentle method.

Ansa eh? I think I may just go with Timevalve in this particular application if I have to buy a pipe ;-) Tx for the reply!

t walgamuth · #4 04-13-2009, 12:08 PM

Heat and candle wax is my favorite machinst's favorite fix for a stuck bolt. It may work on your pipes too.

SPDMETL · #5 05-01-2009, 08:31 PM

Heat ! Listen for a faint " tink " noise- it tells you it released

compress ignite · #6 05-02-2009, 02:52 AM

by Kano labs

Spray it on recalcitrant bolts/nuts and leave it on overnight.

wbain5280 · #7 05-02-2009, 06:14 AM

This might hemp:

http://www.ssimports.biz/gallery/main.php?g2_view=core.ShowItem&g2_itemId=1129

compress ignite · #8 05-02-2009, 05:36 PM

wbain5280,

Are replacement manifold tips available (AND from whom?)

Thanks!

todds · #9 06-10-2009, 03:06 PM

Welp, I've given up with these damned things. After many applications of PB Blaster and long sessions with a MAPP gas torch, sledge and a pry bar I'm finally done with it. It's sawzall time! I guess I'll have to buy a new front pipe...

I managed to actually remove all the flange bolts oddly enough and the flanges are free and spinning around. I heated up the manifolds so much they changed color and parts of them started smoking, also I banged the stuck pipe so much that it dented in a few places. The pipe and manifold are the exact same color, rust! I think they've managed to weld themselves into one.

I plan on giving the manifolds some electrolysis and a coating of jet-hot if I ever get it off. Perhaps a new stainless front pipe..

Shawn T. W. · #10 06-12-2009, 09:23 AM

Quote:

Originally Posted by todds

Welp, I've given up with these damned things. After many applications of PB Blaster and long sessions with a MAPP gas torch, sledge and a pry bar I'm finally done with it. It's sawzall time! I guess I'll have to buy a new front pipe...

If you do cut it, why can't you cut it in a place where you could slide a coupling over it, and hook it back together later?

Shawn T. W. · #11 06-12-2009, 09:24 AM

Quote:

Originally Posted by t walgamuth

Heat and candle wax is my favorite machinst's favorite fix for a stuck bolt. It may work on your pipes too.

Tom, Can you explain this procedure in more detail please?

todds · #12 06-12-2009, 09:30 AM

Well, I still have to get the other end outta the manifold. I don't think it's going to end up being re-usable. Somebody used SAE nuts and bolts on the flanges so I don't think the exhaust was installed with that much care to begin with...

todds · #13 06-19-2009, 01:50 PM

Alright, in the battle with my exhaust the sawzall emerged victorious as it always does.

The loser, my exhaust pipes:

The next problem, how the heck to seperate the manifolds! With the bolts the way they are, can't exactly use the same trick...

My craftsman metric 12 hex box wrenches and crowsfoot just round the bolts, if they started as 12's they're more like 11.5 now. I'm going to try PB Blaster and the sharpest toughest little vice grips I can find next. The problem is the four inside bolts, I think I can just hack off the four on the outside.

Damn, my valves are filthy!

VintageBenz.org · #14 06-21-2009, 11:41 AM

Hey Todd, I would ask how you've been but by the post answers my question!

Now you got me all worried about doing mine! It sounds as though I have an exhaust leak and thought there were gaskets that needed replaced along the collectors. Is this not the case and should I be looking elsewhere for the leak?

That *tick tick tick* noise is really getting to me!

Tomguy · #15 06-21-2009, 02:06 PM

Your solution now is dremel the heads off the studs, then once you get through enough you can use a metal chisel + 2lb mallet to snap them off. Once you have the 4 off you should be able to pry the manifold apart. Then you will need ample soaking with PB Blaster on those studs for at least a day or two. Then heat the studs until cherry red with a blowtorch, and put vice grips tight on them, they should come out.