how to get off frozen bolts?

I'm trying to get a manifold off a Honda Civic in order to replace the
clutch. The book calls for removing the exhaust manifold. Off course the
bolts/nuts are frozen. I have soaked them for a couple days in penetrating
oil and still no go. Is it possible to heat them up with a torch and have
them come off easily??? Or will they still probably break off??

thanks in advance

Gary

 

If you heat up the bolts without heating up the heads, the bolts will expand
(get thicker) and probably get tighter. If you can heat up the heads around
the bolt hole without heating up the bolt then the hole should expand
without the bolt expanding, it MIGHT get a bit looser. I would caution
against heating the heads too much in a localized spot, it might be possible
to warp the heads.

You might also try (if you can get at the bolts without burning your hands -
again, at your own risk) running the engine a while to get both the bolts
and heads hot. the aluminum will expand more than the steel of the bolts -
they might be easier to remove. Just don't heat just the bolts, that will
probably do the exact opposite of what you want.

I'm just using suppositions here from a little knowledge of physics, I
haven't tried any of this - so use these ideas at your own risk.

Can you get at the bolt heads with a hammer? Tapping the bolt heads
(straight on) might help loosen the bolts. Don't hit them too hard, if the
heads are aluminum (they probably are)you don't want to damage the threads.
This method I have tried. Have you ever tried to get a stuck lid off a jar?
Banging it on the counter frequently breaks it loose.

Best of luck

 

What year of Civic is it?

I know on mine, you DO NOT need to remove the exhaust
manifold (a 98 LX). Also, on my 87
prelude, we didn't have to do anything like that to
replace the clutch. I could see at the very most that you
might need to remove the exhaust pipe, if it runs under
the trannie, but otherwise, if there is no interference
with the trannie side of the engine bay, I would not bother
removing the exhaust manifold.

Haynes and Chiltons are famous for telling you to remove
stuff so you can have easy access to whatever you are fixin,
but in many cases these steps just create a world of
frustration, as you are probably experiencing now.

A good example is when I did my Alternator (although this
repair is definitely not on the same level as a clutch
replacement), Haynes said to pull the driveshaft out to
gain access to the alternator. After looking at it really
hard, (and busting a ball joint from trying to take off
the driveshaft), I realized that there was a simple
mounting bracket that could be removed, instead of having
to drain the trannie, pop the ball joint, and pull the
drive shaft.

However, if you are really stuck on removing the manifold,
applying heat (carefully, there are some areas like the
head that you don't want to apply a torch to), can loosen
the most stubborn exhaust bolt.

Good luck,

t

 

Try the penetrating oil "PB Blaster." It's available at Autozone, Checkers,
Wal-Mart, and the like for around $5 for a large can. It's the very best
penetrating oil available commercially.

Incredible stuff. Since I started using it last year, I haven't met a bolt I
couldn't free. I have done a fair amount of exhaust system work this past year,
too, including disconnecting the exhaust manifold header from my 1991 Civic.

Let soak five minutes, try to turn a bolt. If no go, soak again. Tapping
carefully with a hammer may also vibrate free some of the rust etc. holding the
threads tightly as well as help the PB Blaster reach farther.

Better, let soak with PB Blaster over a day or so, with some driving in between.
Repeat for a few days.

I have been spraying the PB Blaster into an old tuna can and then using an eye
dropper or syringe to better direct the PB Blaster on hard to reach bolts.

Also, one of the 14 mm hex head bolts at my exhaust manifold had so corroded
that a 14 mm socket would not work. I tapped a 13 mm socket into place and
voila, it came off.

I replaced all bolts.

I trust you are using breaker bars or pipe extensions fit over your wrenches to
give you extra leverage, yes?

That's vital. The aforementioned bolt still didn't come off without a 3-foot
pipe extension on the breaker bar/ratchet wrench.

 

Caroline,

Do you have to remove the exhaust manifold to do the clutch?

This guy has a 1989 civic, similar to yours, right?

t

 

I think Ropert's Aloha probably made a post-o. From my reading, you're right
that the exhaust manifold doesn't have to come off, but the exhaust header does.

My take:

I didn't see where Ropert said what year his Civic is. From googling he's said
in the past he has a 91 Civic. I too have a 91 Civic, manual transmission.

My previous post was with reference to my recently removing the exhaust manifold
header (not the exhaust manifold itself) to replace the oil pan gasket. It's not
possible otherwise on my Civic.

I'm pretty clueless about repairs to the clutch and transaxle, but I do remember
that there was what looked like a transaxle (ring? = flywheel?) gear cover plate
just to the (car's) right of the oil pan. The cover plate had to come off to
remove some oil pan bolts. A couple of the oil pan bolts on the right actually
supported this cover plate IIRC. Some support bolts for the exhaust header were
also interference at this point.

But I can't see why the exhaust manifold would have to come off. It sure sounds
like Ropert made a post-o and meant he was trying to free certain exhaust header
bolts, the exhaust header being the pipe that directly connects to the exhaust
manifold, just beneath where the O2 sensor is (at least on my Civic).

In support of this:
1.
My Chilton's says that replacement of the "clutch driven disc" and "clutch
pressure plate" requires removal of the transaxle. Sure enough, the steps for
removing the transaxle say to remove the header pipe.

2.
Same at http://www.honda.co.uk/owner/ConcertoManual/62sk301/8-5.pdf . See the
bottom drawing on page 2 and step 12 on page 2, for a 1991 Concerto, whose
engine I think is the same or nearly so as the 1991 Civic's.

3.
Same at http://www.honda.co.uk/owner/CRXManual/62SH200/8-4.pdf , bottom drawing
on page 2 and step 12 on page 2. The drawing of the header here looks more like
my Civic's.

 

He emailed me, and mentioned it was an 89 he was working on.

I am really certain that the exhaust doesn't have to go
anywhere to get the transaxle out. I've done clutch work
on an 87 prelude, a 93 accord, and a 98 civic, and all of
these were fine without removing any exhaust parts
whatsoever. Ropert mentioned as well that it didnt' seem
that there was any interference from the exhaust anywhere,
but I was curious, and I know you have a similar car.

But hey, I could be wrong....

t

 

Tuna? TUNA? All this and you cook, too?

I must have a talk with my wife.

JM

 

I am a terrible cook; I burn water. So maybe tell your wife how lovely she is
tonight.

And, uh, if you have any single male relatives who can cook, are slim, use a
pleasant after shave, but don't know the correct end of a wrench, you know where
I am...

 

Wow thanks so much to you all. I did misstate about the exhaust manifold. It
is the "exhaust header" that the books(Haynes and Chilton's) say to remove.
But I can't see any reason to remove as the header is off to the side of the
transaxle. I figure I'll take everything off and try it without removing the
trans. I did buy some PB blaster and am soaking the header bolts just in
case...


thank you all so very much

Gary in Hawaii

 

Hi Ropert, I'll look forward to any update you'd care to provide. I for one
anticipate having to replace the clutch driven disc and clutch pressure plate
sometime in the next 50k miles. (My 1991 Civic LX has 154k miles on it, original
clutch.) Per disallow-t's posts, I'm certainly going to hold off removing the
exhaust header until and if I see it's absolutely necessary.