Hi guys,

I ordered the Flowmaster downpipe and crossover kit. It should be arriving tomorrow. I have made an appointment with an exhaust specialty shop to install it. What can I expect during the install? From what I can tell, they will need to remove the front passenger wheel and the inner fender in order to access the connection to the turbo, and they will either have to cut off the bolts on the flange connecting the downpipe to the rest of the system (looks completely rusty to me), or even cut it off in order to weld it.

What did you guys need to do?

Sincerely,

Rob :)

Woah! You don't need to take anything of the inner fender or wheel off. I did mine from the top, there is only a band clamp holding it to the turbo at the top. The bottom, well, you might have to bust them off and drill them out to put bolts in if they are beyond saving from rust. Everything else can be done from below the truck.

Soak the crossover bolts from above with penatrating oil the night before removal. I never have any problems using an impact driver and a 15mm socket to loosen them.
Get a pair of exhaust donuts for re-installation.

Thanks for the replies, guys. You are so helpful, and I do appreciate it. I'm hopeful to get this all wrapped up before a big road trip with the family. Also purchased some equipment from our buddy John Kennedy to remote my PMD.

Thank you again,

Rob :)

Rob, FF is right - WHOAH!! Everything is accessible from the top/bottom. Just make sure that when the shop reinstalls the clamp from the turbo to the downpipe that they face the the nut towards the front of the vehicle so you can get a deepwell socket on it in the future.

Thanks minisub, I forgot that part.:o:

Also, it is TONS easier to get to everthing if you unbolt the coolant bottle off the firewall and move it out of the way. You wont lose any coolant (no need to disconnect the hoses).

First time I did my band clamp, it took HOURS of cussin and fighting. Then next time I had the coolant bottle out and it was easy as pie.

Tim

Ooh! Great hint! I think that removal of the air cleaner might also help.

You guys are the best. Thanks for all the hints!

Sincerely,

Rob :)

When I did mine I pulled air cleaner and the bottle. Worked like a champ!

Removing the air cleaner alone did it for me

Update - just talked to the exhaust shop. The have halted work on the 'sub, claiming that they absolutely can't get the bolts off the crossover nor the downpipe. They claim that the only bolt they can get loose is the one for the turbo clamp.

They also say they *might* be able to unbolt the downpipe if they break the bolts off, but that they need 'case-hardened' bolts to replace them, which they say they don't have. I looked in the Flowmaster box, and it seems to come with nuts and bolts - I thought those were for replacing the ones you would probably break.

They want me to take the Suburban away, until the penetrating oil has a chance to work and they get some bolts in, and bring it back in a couple of days. Rats! I thought this would be an easy job.

Frankly, I'm a little shocked they couldn't do this - they are, after all, an exhaust specialty place.

What do you guys think?

Sincerely,

Rob :)

Your being told a story...... Period!any good shop would have that sucker out in minuits I've never see W-D 40 work better than a torch, "Wait for the wd to work" hummm that stuff would have burned off before you left the driveway of your house!My advice find another muffler shop!Nick

I don't have any experience in this but that sounded very strange to me. That a proffesional exhaust shop shouldn't be able to do the same job alot of diy folks do all the time.:confused: Doesn't sound very proffesional to me. I think I would consider ditching that shop and tracking down someone who could assist you in doing it yourself instead. :grd:

Mine being a 00 was very rusted in such a short period and we could't break em no how without twisting them off even though they had soaked overnight with WD, ended up using a liquid wrench to get them to move a little and then letting them soak another day with WD, they came out the next day without heat.

I just torched mine out:D

Chicago TDP, do you mean to say you heated the bolts holding the crossover on with something like a soldering torch (e.g. propane type)? Can you describe what you are doing?

Sincerely,

Rob :)

Seems like your muffler shop is somewhat less than professional. Praobably just after the fast buck.

Bring it home, soak the bolts with Kroil (the mystery oil) and give it a shot in the morning. If that doesn't work, use a 'hot wrench' (aka torch).

BTW, aren't these actuallly studs and nuts ? If that is the case, most exhaust systems that I've worked on with a stud/nut combination used a 'softer' metal for the nuts so that they could be chiseled off. Something to consider.

OK, the shop does not want to work on the truck because once they turn them bolts, they gonna break:o: and then they are resposible and have to fix it. THey only way to fix it them is drill them out and in that case, the manifold must be taken out.
The cross over bolts are very fragile. They have been through so many heat cycles that they are ready to snap, not to mention that the rust is also holding them in.
When I took mine out, it took me about an hour per side to get them out. I have to heat the cast iron manifold red hot. THen, SLOWLY, turn them little by little. Lots o Patience;) .

Thank you for all the quick, informed, and highly valued feedback. I'm continually amazed by how useful the responses are in this forum, and how selfless this group is.

I'm going to put some penetrating oil on the various bolts and give it some time to soak and I will get back to this project another time. (There's a family road trip coming up and I don't want to disable the vehicle by accident.)

BTW, if the crossover pipe bolts are very fragile, then perhaps I should replace them when I finally do get them out. Can anyone tell me the proper size/length?

Sincerely,

Rob :)

UM, metric for a fact on my '98. I think mine are like a 12 mm bolt, bout 1.5 inches long

I'm with TDP find a shop that will torch them out, just went through this on my 97. Amish neighbor owed me and he has a torch, he had them out in about an hour. Just get them red and slowly turn them out. Get new bolts cause there was no way I could reuse the old ones, they are metric just can't remeber what size.

Update - OK, I went to the exhaust shop pretty miffed, because they had toyed with the 'burb all day and didn't get anything done. It was very inconvenient to take time off work, ask my wife for a ride, and then have to ask her for another ride just to pick up a car that hadn't had any work done on it!
:rant:

(Actually, I had an 8AM appointment, but when I arrived at 8AM, he said he couldnt' get to my rig right away becuase he had some other cars in the bay that had just come in the night before. In my view, why have an appointment then?)

I am probably going to do these myself. I purchased a can of PB Blaster and will soak the bolts. Maybe I can check with the dealer on the correct size. (Is it possible to use stainless or brass for the bolts to keep rust from building up?) Anyway, I'm thinking I'll need to use my propane torch and a six-sided socket to turn them out slowly. Any hints or words of wisdom are certainly solicited!

Sincerely,

Rob :)

Rob
On the older chevs you can get a brass type nut, The studs would be steel, propane will help, but not as good as a torch.
if you soak em then heat 'em up. work them tight and loose very small turns at a time, edventually they should free up, I take it you are going to remove the studs not the nuts, if so give it lots of heat

Good luck!!!!!!!!!

Keep the fire extinquisher handy (LOL)

I installed my 3inch Flow Master Kit tonight it took me about 1.5 hours, I was not trying to break any speed records, It went smoothly as I removed the Air box to access the turbo clamp. my Cross over had bolts in them instead of studs, and even if I had busted them off they can be drilled out with no trouble (well maybe a little) and a nut and bolt could be used, you would just have to drop a size on the bolt. all of the manifold flanges bolt holes go straight thru (no blind holes). I don't know if this helps any one but I found it easier to put the x-over on last as it gave more room to feed the down pipe into posn.
Someone said it before the factory down pipe looks like it was driven over by a truck! they were not exergerating.
I found I did have to bend my tranny cooler lines away from the exhaust pipe as they were actually touching , also up near the downpipe clamp I had to zip tie a coolant heater hose away from the exhaust as well.
Looking at the rest of my factory exhaust I was thinking if I cut the pipe just after the flange and just before the Cat I could run straight pipe (10 foot length) just before the axel, then have the D-Max tail pipe installed. So will the straight section of pipe fit in there without hitting the cross members??

NickG,

Congrats. glad to hear that it went well. Can you answer a couple questions?

1) What is the size of the bolts holding the crossover in? When I checked with the dealer, he said they had torx heads on them(?)
2) Did you replace these bolts? If so, what did you use?
3) Did you put new gaskets into the crossover, like these? (http://www.ssdieselsupply.com/product_116_Crossover_pipe_hitemp_gaskets_pair.htm l)
4) Finally, what difference have you noticed in performance?

Thanks so much!

Sincerely,

Rob :)

Rob
My bolts did not have torx heads and if they did I would not put them in as you would never get them out later. I don't know the size except they are close to 3/8 crse thread, I'd guess 10mm, they were about 1.5 inch long. I just left my donut gaskets on the manifold, as they were in good shape. I don't have any leaks....except a tiny one at the pipe flange, which I will address once I cut out the Cat & Muffler. BTW the bolts that come in the kit are just a plain old grade 5, nothing fancy.
As for performance, I cant say yet as I finished late last night, and only drove into work this morning, seemed peppier, although it was hard to say, but it would have to be better after looking at the down pipe...man is that thing ever restrictive, I expect to see some improvement once I get the rest of the exhaust up to a larger size... I'm off to the local parts place to pick up my 3.5/ 10foot length of exhaust pipe.

Sorry I dont know the size, but I can pull a bolt back out and give you the size and pitch, If you can't get one out. But as I mentioned above be prepared with a couple of smaller bolts with nuts, in case you are unfortunate and have to drill then out.

Good luck with your manifolds
Nick

Nickg, Flowmaster also makes 3", 3.5", and 4" universal tailpipe kits. I have used them and they are sweet! You could go from the 3" intermediate pipe to a 4" tailpipe kit, looks killer and gives a bit deeper tone.:ro)

FF,
Thanks, any chance you know the part number? seeing as the parts folks don't have the ability to look it up......I guess I'll visit www.flowmaster again
Thanks again
Nick

Rob
The bolt size for the manifold to cross over flange is 10mm (diameter)X 1.50 (Pitch) X 30mm (long). at least thats what fit into mine. You should be able to buy them at just about any parts store.

Nick,

Thanks. It's very kind of you to get the exact dimensions for me. I'll be sure to have extra bolts on hand (when the Chevy Dealer's parts guy told me that the replacement bolts had torx heads, I about fell off my chair!). The Tahoe and 'Burb are both from the East coast - there's a goodly amount of rust on the exhaust components.

I have visited Edmonton - great place - friendly folks!

Sincerely,

Rob :)

Rob, as a side note...

When I pulled my engine, I took off the x-over, probably for the first time ever since it left the factory in '94. I hosed it with the PB Blaster and all 6 nut came off clean. It took a goodly amount of strain to break them loose, but once moving, they came off easily. Dont fear this, you should be ok

Tim

Use WD40 on the downpipe flange over night, then heat the nuts with a torch until they are red, and you should be able to loosen them, one after another. Once they are loose, you can screw them off.

I didn't know they were supposed to be sensitive, so when I pulled mine off the other day, I actually just put some squirrel juice on them and then used a 3/8 impact.

Haulin65, if you read the entire thread, you'll see where the exhaust shop I went to was unable to complete the job, even when they had my rig the entire day. The downpipe I am less concerned about, as the flange that has the rusted nuts is easily accessible, and the worst case analysis is that I cut the nuts off, pound out the studs and proceed from there.

The bigger area of concern is really the bolts holding in the crossover pipe, because if I break one off, I might need to pull the exhaust manifolds and then drill them out. (and who knows what else I'll break off in that process) I am more confident of doing it myself (on 2 vehicles) given the encouragement and expertise of the guys on this forum.

I'll likely attempt this in a couple of weeks, as I have a lot of activities that will preclude any kind of 'car down' scenario in the near future.

Anyway, this is a super super forum with very gracious and knowledgable members, and I greatly appreciate the help.

Sincerely,

Rob :)

I was just trying to throw a little humor in about my lack of knowledge on getting them off...;)

Seriously, though... I already took the right side manifold off of mine when I replaced the injectors and it wasn't really that bad. I don't know about the left side, but since it doesn't have the turbo on it, I'd guess it is probably even easier.

Anyway... Good luck with the down pipe either way. I will probably be yanking my whole exhaust before long anyway to go with something a little bigger.

And I agree... folks around here are great with all of the assistance they provide. If it wasn't for this site, I probably would have gotten rid of my truck shortly after buying it!:lol:

OK, here's an update.

This morning I called the local Midas shop. I'm friendly with the guys down there, and they seemed to be on the level. I explained to the store manager that I wanted the crossover and downpipe installed, and he said "Sure, sounds like a 1 hour job. My guys can do that, no problem." Anyway, I scheduled an appointment and went down with the kids. Note that I had soaked all the nuts and bolts with PB Blaster the night before.

The technician had no problem with the downpipe, as he simply broke the bolts off at the flange (The idea being to use the bolts that came with the FlowMaster kit). To my surprise, he actually did decide to take the inner fender off (it took him like 10 minutes to do), and so he had full access to the downpipe. It went in easily, but he did damage the flange gasket. I told him to cut the flange off, and simply weld a pipe over the top to join the two pieces. 20 minutes later, he was done. Looks good. Here's where it gets dicey.

I took the kids off to treat them to an ice cream cone. When I returned, I was horrified to know that in trying to remove the bolts holding the crossover pipe, they had managed to break off 5 of the 6 bolts! Augh! When I asked them why they did that, they said that the first one broke off, and they decided the easiest thing was to break them all off and then drill out the holes and replace them with new nuts and bolts. It sounded reasonable, so I sat back and waited, and waited, took the kids to a restaurant, and waited and... you get the idea.

I returned 3 1/2 hours later, to find that they had been completely unable to remove the remainder of the bolts. They had ruined a couple of brand new titanium drill bits trying to get the bolts out. The also tried 'blasting them out' - which they explained to mean that they tried to melt the bolts out with a welding torch. They had stopped because they had failed, and the mainfold was starting to melt! :help:

I surveyed the damage. The manifold still looks reasonably OK, as they stopped when the corner of the flange started to melt. If the bolts can indeed be removed after all this, then they will be able to put some bolts in and salvage the job. If they fail, then new manifolds will need to be ordered, the job will then become that of removing the exhaust manifolds and putting in new ones and replacing the $50 crossover pipe. What a mess.

They are bringing in a senior tech from another shop who has 30+ years of experience in dealing with issues like this, and they hope he can salvage this situation.

Any helpful hints at this point will be appreciated. I can't believe this is now so screwed up.

Sincerely,

Rob :)