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So I need to remove the plate on the bottom of the bell housing so I can check the thrust bearing and spin the flywheel around so the metal cap of the CPS can fall out. I have 1 nut dremeled off but the bolt will not pound out. I've tried some heat on it but still no movement. Do the bolts actually come out? Do I need to apply more heat (I got it warm but didn't know how far to go so stopped before going too far)? Are there any tricks I should know about to get the exhaust pipes off the manifold?
Thanks.
You're referring to the bolts that hold the catalytic converter pipes to the exhaust manifold? 3 M8 bolts per side, they definitely come out. Got a pic of where you're stuck?
You're referring to the bolts that hold the catalytic converter pipes to the exhaust manifold? 3 M8 bolts per side, they definitely come out. Got a pic of where you're stuck?
Yep, those are the raskals I'm talking about. Sorry, reread my orig post and jumped right over the fact I was trying to lower the exhaust to get to the bell housing plate. I'm having trouble with the exhaust bolts.
If the bolts are original then they are most likely not coming loose. When I tried to remove mine on my 87 I simply twisted the nuts off. As Rob said they are M8 bolts, I believe there is one longer on the driver side to accommodate a bracket so remember that. Otherwise brute Force works.
I'm interested in best practices for removing utterly rusted/fused bolts like this, without damaging the flanges-
1. Beg/borrow/buy an induction heater? Not sure that you can get enough heat into a flange to release the bolt, but maybe?
2. Drill or break the heads off the bolt, center punch the bolt shaft, and start drilling bigger and bigger till you get to the diameter of the hole in the flange?
I have the same situation on the muffler bolts on this early '78, someone used crappy hardware with their homebrew RMB.
Huh... I’ve never had an issue with the exhaust bolts/nuts.
Did somebody replace them with grade 10 or 12 bolts?
The nuts either come loose or I twist the seized nut and the tip of the bolt right off. Doesn’t take much effort even. The bolts are often so old/rusted/corroded/baked that they snap with less effort than is required to torque them to spec.
Replace with correct length replacement new 8.8 bolts and nuts. Go crazy and get copper exhaust nuts if you want to splurge.
I've been working on 1 bolt on the exhaust and didn't want to get too crazy and monkey something up. I have the nut dremeled off but the bolt won't hammer out. I was careful not to cut the bolt off at the flange, so there's a stub left. I heated the bolt and flange but the bolt is stuck and won't hammer out. I didn't apply a lot of heat as I didn't want to cause a bunch of damage before I knew what I was up against. Getting ready to head back to the garage to try again.
Ok, couple of stupid questions. Which bolt is stuck? Are all the other bolts out? If yes, have you tried to wiggle the exhaust or taken a hammer(large) to the flange to loosen the bolt in the hole?
I'm interested in best practices for removing utterly rusted/fused bolts like this, without damaging the flanges-
1. Beg/borrow/buy an induction heater? Not sure that you can get enough heat into a flange to release the bolt, but maybe?
2. Drill or break the heads off the bolt, center punch the bolt shaft, and start drilling bigger and bigger till you get to the diameter of the hole in the flange?
I have the same situation on the muffler bolts on this early '78, someone used crappy hardware with their homebrew RMB.
Not wanting to start a battle over penetration lubricants as I know everyone already has a personal favorite, but I stumbled across Kano Kroil some time back and I now swear by it! The rusted on exhaust bolts on my '87 came right off without any issues after a few squirts of the stuff and a five minute wait. The list of other 33 year old stuff that I've removed from the car without issue is quite long, including dried on hoses that seemed impossible to get off without tearing them that then slipped right off after a quick squirt of the stuff.
I've been working on 1 bolt on the exhaust and didn't want to get too crazy and monkey something up. I have the nut dremeled off but the bolt won't hammer out. I was careful not to cut the bolt off at the flange, so there's a stub left. I heated the bolt and flange but the bolt is stuck and won't hammer out. I didn't apply a lot of heat as I didn't want to cause a bunch of damage before I knew what I was up against. Getting ready to head back to the garage to try again.
No heat needed, those bolts remove freely and have plenty of room to do so. That bolt may be rusted in place or have the weight of the exhaust pressing down on it, or both.
You removed just one nut from one of the three bolts on one side, correct? Take the other two bolts off that side and the three from the other side. The system has some weight to it so it may break free after the other bolts are out.
Just to put a bow on this thread...
I took my dremel and ground the nuts off the bolts.
Then before applying heat, I tried a hammer and punch to persuade the remaining bolts. Started on the driver's side. The bottom bolt came flying out after 3-4 shots and one of the upper bolts came half way out from the force of the lower bolt. The 3rd (long) bolt took a bit more persuasion, but eventually it came out too. Moved to the passenger side. The lower bolt was the 1st one I tried in this whole endevour and it was stuck. Moved to the top 2 and they both came out. Took a small screwdriver and tapped on it between the flanges, being careful not to cause any gouges. It popped. I hammered the bolt and it came out. 6 bolts out.
Had to buy a 27mm open end wrench to get the pipe to the cats off. Took me to 3rd try but found one at an Advanced Auto. Used a 22mm flared wrench on the bottom nut. The 27 wouldn't budge. Ended up putting some heat on the nut and it broke loose. The exhaust pipes are down, the bell housing plate is off, and the CPS is in.
I got the fuel lines back in this afternoon. Back on track for a starting attempt.
Appreciate everyone's input.
Last edited by husker boxster; 03-24-2020 at 05:36 PM.
that looks like a bogus crank sensor,
I suggest you buy a Bosch part and swap it out.
NOTE it may work at first but after a while the less expensive replacements start causing running issues.
Thats what I have seen,
now when I find a non standard part like this i replace it no questions asked.
NOTE as an option buy a Bosch CPS and toss it in the spare tire well parts bin,
that way when the engine stops running you can swap it in before the tow truck arrives
NOTE as an option buy a Bosch CPS and toss it in the spare tire well parts bin,
that way when the engine stops running you can swap it in before the tow truck arrives
^^ this ^^^ with a tiny bit of revision: Install the correct part in the correct place now. Take the old one and add it to the ride-along spares box, on the off chance that the correct one fails you on the road somewhere and you feel capable of diagnosing and repairing it there. As much as I love the idea to run-to-failure on some pieces, they need to be pieces I can diagnose instantly and swap out in a few minutes while out wherever it happens to fail, all with tools I happen to have riding along. The CPS doesn't fit this profile, in my casual experience. So it would get changed prophylactically in the comfort and convenience of my workbay, on my own schedule, rather than on the side of an Arizona highway in July. Just sayin'...
I had a long battle with the CPS (ironically it was working fine albeit original, so I went preventive route) recently. When I finally got the old one out, I used anti-seize on the bolt and the CPS shaft of the new (Bosch/Porsche) replacement after thoroughly cleaning out the deep CPS hole.
Also last time I dropped the exhaust at flanges, replaced the metal gaskets along with all new hardware, and again plenty of anti-seize though I don’t know if it’s still effective in a location with so much heat.
03-05-2020, 10:04 PM
Exhaust Manifold Flange Bolts
