I have worked on hundreds of cars....all brands, all makes and models. Hate the new stuff. So lets figure this out....what is the worst, most aggravating, knuckle busting, have to go google it thing you guys find when working on cars. I will get it started. I HATE redoing drum brakes. Hate it. Just did them on a 77 Bandit Trans Am. Bounced a spring off my forehead...didn't have the right fancy brake tools to seat everything. Got sent wrong park brake lines. Chime in. Lets all vent.....Body work is best left to professionals, its a work of art to cut off half of a car and make it look like it never happened. Electrical issues are a nightmare. Agreed. Lets hear the horror stories. Ever tried getting a tire off a car thats been sitting for 40 years? I just wonder what everyone else has come across. Share your worst stories....
Dave in Colorado

Replacing rusted brake lines. Just did my son's car, ALL of them, used several 25 ft rolls of brake line, flaring, bending, new fittings, etc., and that's just part of it. Removing the old, rusted lines and getting the old, rusted fittings loose I hate doing brake lines and brakes too.

On brake lines, I usually see people trying to use open end or lines wrenches on the fittings.

If you're replacing the lines, cut them off and use a 6 point socket on the fittings.

even better. use a induction heater to warm them up before trying to remove.

Brake lines are easy if the cars apart. I just reinstalled door glass in a Duster. Box of pieces that were removed from several doors that I didn't disassemble. Service manual pics and instructions were terrible. Who new that the bottom glass channel could bolt and and fit perfectly upside down. And then the glass could only go up half way until 2 small pop riveted wedges stopped it. I've done nearly every thing during restorations. Stainless/aluminum trim repair, paint, weld, structure replacement, engine, trans, axle, wiring. But never a head liner.
Doug

Take it all apart in the first place......

I always find that a second set of hands when doing drum brakes is incredibly helpful. I normally cheat in this step and enlist the help of older friends that were around when drums were pretty much all they had, they're really familiar with them and normally have all the old tools.

I cheat with rusty brake lines most of the time too. Have some people that work relatively cheap and just take it to them, "here, it's your problem, call me when it's done". Depending on the car though, I will do everything I'm capable of. The cars I really care about, I try not to let other people touch. In these rusty brake situations, a lot of penetrating oil and heat are a big help.

I think the biggest things I hate are electrical and other people. When restoring cars, I pretty much want everyone else's hands off of it, I want to do it all because I'm meticulous and anal. I've had to work over other people's work and a lot of the times, things were just not done to my standards, and it bothers me. For example, I helped my father-in-law restore a 55 F100 5 or so years ago. Had a company blast the cab for us. I planned to epoxy the cab but, my father-in-law said that they'll do that too and that's the way he wanted to go. We get the cab back and there are huge runs in it all over the place that I had to sand out. When sanding in certain areas, I run into the original paint, so; I know they didn't blast everything correctly. We flip the cab up and they didn't even blast the bottom side. He asked me what I would do, I told him to take it back to have the bottom blasted because that would be the correct way and he paid to have the whole cab blasted. He didn't want to do that, so; we POR'd the bottom of the cab and I painted it. Everything turned out great but, to this day, it bothers me that the underside of the cab wasn't done correctly. All of this caused me a lot of extra time and impacted the quality of the final product. You can't tell any of this by looking at the truck but, I know it's there.

Wonder if there's a connection there. The tools are neither fancy nor expensive, A divot in your forehead though...

I don't do restorations.

My biggest issue with any car is undoing PO and shade tree mechanic hacks.

Scraping 50 year old undercoating off of the bottom of a car getting it ready for paint. Never again.

Drum brakes are a pain, but not that bad. I assemble them on the ground prior to disassembling to the old ones and use a pair of needle nose vise grips to pull the springs in place.

Been using nickel-copper tubing with stainless tube nuts on all my brake projects for years now. Will never go back mild steel living in the rust belt.

This^^^^

.Anything to do with re-installing windows! There are always parts broken or missing, non scratched glass is tough to find, aligning them just sucks. Unless you do them all the time it is hard to remember how the regulators get installed and where all the parts go. Busted and scratched knuckles is the biggest issue...

re-doing other's previous "repairs".......
i have done several headliners, and find them not too bad to do.
however, i did a replacement ABS plastic one that replaced the cardboard original with the help of my one buddy, last thursday.
WHAT A PAIN IN THE AZZ THAT WAS !
i tried and tried to convince the owner a conventional bow style headliner would be better,but no........
ACME is the only brand available, and i should have instantly thought of the RoadRunner and Coyote cartoons.

I don't mind drum brakes but hate doing them on multiple makes each with their own way of doing things.

It seems like everyone has their own way of fixing wiring and everyone seems to complain about everyone else doing it the wrong way.

I hate working on a car that someone else either already started working on before and left things apart or didn't put them back together properly.

And it's more of a picky thing but I hate seeing something that's been restored or even worked on before where someone randomly threw the screws and bolts back wherever or replaced them all even when they didn't need to me and didn't bother trying to match the existing ones. Both in appearance or size and type.

I don't mind body work but being an amateur at it it bothers me when I can't get it looking perfect and annoys me, mainly on cars that are being driven and not restored, spending time on body work only to have it start rusting again or paint peeling or whatever else.

Give up on the restoration midway through and then let it sit for decades.

Rear main seal in car

Window tracks

Finding all the butchered stuff the last guy did. Wires smashed in between parts they reinstalled without care. Flex lines with 3/8 hose jammed into 5/16 fittings(not sure how they did it without splitting line, but they did and man was that a scary find up on the engine.)

I can think of more, but have tried to suppress memories.

Anything to do with rust repair. Cutting, grinding, welding.

Wiring repair followed closely by bodywork and paint! (probably why my car is still in epoxy primer)

OMG !!! THIS !! . . . actually the back windows on my 70 Sport Satellite !! I swear that they must have installed the window regulators & glass, BEFORE they put the 1/4 panels on ! If anyone has ever done the regulators & rear windows on a B Body . . .they know !! LOL . . . I am sure I "donated" a pint of blood from all the scratches and scrapes doing them ! And, then the adjustments . . . . UGGGHHH !!! . . .

on a sport fury convertible the previous owner had cut the inside skin to peel it open so they could get to one of the rear qtr windows. he bent it back in place when he was done. I figured out how to get the other side apart without the need for a cutter, but I really did think about doing the same thing. lol.

Interesting.

Taking them apart isn't so bad to me, it is getting every little detail just right on reassembly.

Maybe we should work out a deal.

My vote goes to blocking/sanding/priming. It seems to be a never ending process, especially with a bad back and shoulders.