Somewhat alive 75 450SE - Part Three

Figured I'd start another thread as the previous one was starting it's second page! I hope y'all don't mind my public head scratching, musings, ramblings, and venting, but it makes me feel better!

Went to the 'yard yesterday for some various widgets and found an excellent looking set of Bosch plug wires so I snagged them. The ends looked to be in excellent condition, wires were soft and pliable, so I figured they were a keeper. I pulled the cap and all, but I'll get to that later...

I also got (from the same car) a top engine wiring harness (back to firewall) that didn't crack and fall apart when I touched it. In fact, it feels quite pliable and the connectors are not falling apart either! Now I have a dilemma, FedEx just delivered all of my wire, heatshrink tubing, and connectors so I now have all of the materials I need to make a NEW wiring harness. I guess I'll flip a coin...

Getting back to the distributor cap I pulled... It looks like somebody was having fits getting it running (I can identify with that). There were fresh signs of cleaning the rotor and contacts inside the cap. As I said before the wires looked pretty fresh and when I cracked a couple injectors open the gas didn't smell as rank as is normally found in junkyard cars. I got home, put in a fresh set of NGK BP5ES plugs and threw on the cap and wires I had just picked up, crank and crank, no-start! I put my cap on with the Bosch wires and it started. Surely this poor 450SE in the junkyard didn't wind up there because of a bad distributor cap!

When I was changing plugs one of them didn't feel right on the way out. It was the same hole that I have previously ran a thread chaser through and I was getting nervous. Lo and behold, when the plug finally came out, it had a "spring" hanging off the end of it! Hmmm, somebody had put a standard Heli-Coil in there, no wonder it felt weird every time I pulled the plug... Another trip to the parts house, and a $40 spark plug hole repair kit, and the plug is finally installed. I ran the tap through the hole and put a coat of JB-Weld on the outer threads of the proper thread insert so hopefully that one will stay put.

After all of these gyrations I was hoping for a "tire-boiler", maybe my expectations were too high. The car now idles a little better but still misses. It also seems to have very little power, I can't even spin the tires in the grass with my foot to the floor! I do have a couple of lifters/followers too loose so maybe when I get them adjusted the idle will smooth out as the miss pretty much seems in sync with the "clack".

I remember Peter remarking that Techron doesn't burn very good (had a bottle of Techron and bottle of Valvoline Synthetic in about 8 gallons of gas) so I dumped in another 5 gallons of fresh gas only to dilute things a bit, we'll see what happens. I did notice that when I took the AC Plugs out the carbon was starting to burn off and the majority of them were starting to take on a brownish tinge. Waybe that was the result of the fast idle and water i drizzled down the TB the other day.

I was able to free up the mixture pot on the '75 computer so I put it, and it's MAP sensor, back in. It seems the fastest and smoothest idle is obtained by rotating the mixture control full lean (CCW). I have found that a sensor on the back of the R/H head appears to be falling apart, anybody know what this does?

One last thing, my turn signal switch does not stay engaged to the right, left works properly. I checked 5 450s yesterday and the turn signal switch in every one failed to stay engaged in BOTH directions! Is this a weak spot? I have not taken my switch out yet but is this a fixable problem or will a replacement switch be mandatory?

Hopefully, in the future, if somebody gets an old 450SE in the condition that mine was in, these rantings of mine might prove useful in their ressurection attempts. At least maybe they will lend moral support and show they are not the only one whose a$$ has been kicked from one end of the block to the other by this beast!

OK, enough for now...

JUstin B.

[wbain5280]

Do what Don Foster does, of BB fame, and put your cap and plug wires in the dishwasher to clean them.

He claims it works and even posted a pic of it.

I saw that pic that Don posted, almost as bad as me curing exhaust manifolds in the oven!

I just put my old cap back on and all is fine, err... at least it starts...

Justin

[psfred]

Justin:

You DO have a NEW cap and rotor on there don't you?

Make sure you don't have a vad leak -- at this point I'd pull the intake and replace the eight runner seals just to be sure -- they are cheap, and it's not hard to do.

If the valves are out, it won't idle for crap. Certainly, it they are rattleing, you have a problem, as these are very quiet engines for the most part.

Turn signal switch can be fixed with a file -- there are two semicircular recesses into which the roller that holds the switch in position drop, and the edge wears off. Take the switch loose (two or three screws under the rubber cover) and you will see them.

Take a rat-tail file (or an appropriate sized tool in you Dremel) and deepen the recesses slightly, checking as you go. Stop when the lever stays put and takes only a small amount of pressure to pull back -- if you go too far, it will become nearly impossible to return the lever to center!

There is a nice posting with pics of this recently.

Peter

Peter,

Thanks for the tip on the switch, I'll do a search.

I personally have not installed a new cap and rotor but bro-in-law claims to have done so several years ago when "the mechanic" was working on it. Maybe I'd better just to make sure but it doesn't look too worn...

I was starting to get pissed off today so I decided to take a break from the engine and do some brake work, should have stayed on the engine... Took off l/f caliper and one piston frozen and the other very sticky. Put in vise and filled with penetrating oil, hit with compressed air, put in more oil, etc. Finally got both pistons un-stuck, polished them up with 400 grit and reassembled caliper. Pistons feel good, no hang, drag, and feel smooth, will install tomorrow. If the caliper works properly tomorrow will order rebuild kits and finish them off.

Also found r/f inner tierod end is about to fall off, tire has about 3/8" of play and I can see the rod end flopping around!

On a bright note, I won the bid on a set of 1975 450SE Owners Manuals on e-Bay, now I can figure out what all the knobs and switches are supposed to do!

Later on...

Justin B.

[psfred]

Justin:

Sorry, chum, but you just totaled out that caliper. Toss it, get another one from the yard.

NEVER, EVER use anything but brake cleaner to clean a brake piston. Abrasives of ANY kind will tear up the chrome plating on the piston, and it will either leak or stick, no way it will every work right.

Sorry, this is very important.

Same goes if there is any rust or pitting on the piston or bore -- the only place rust or pits is OK is above the piston seal with the piston fully seated.

If the pistons were stuck, the seals are shot and will leak and/or drag terribly.

Brake failure ain't funny in a car that will go 130 mph.

Check the rotors -- the one thing I can promise for any old MB that someone stopped driving is that the rotors are too thin, and the caliper was stuck because the backing plate on the pad hit the anitrattle spring. This cocks the pad, and eventually the piston, so it sticks, and reduces braking power to essentially zero.

I have found that a neglected Benz will need all four rotors, new brake hoses, caliper kits (easy, you should have gone ahead an done it rather than sanding the piston!), and sometimes a master cylinder kit. Better safe than sorry, and not all that expensive, Get new pads, too. I got lucky on the 280, the rear pads and rotors were it good shape, but only because on of the rear brake lines leaked. Front pads were gone, and rotors were too thin -- had to stand on the pedal to stop the car, quite scary. Had to replace the wheel bearings, too -- grossly overtightened.

Check the other tie rod and drag link joints, also the steering coupler between the steering shaft and box -- the rubber bushings are surely gone. Check for play (vertical) in the idler arm bushings, too. All common front end stuff.

Peter

Crap, I have done this procedure on domestic calipers (years ago...) with good results. There was some rust on one of the pistons and a light spot in one of the bores so I didn't feel I had much to loose!

I do have new rotors for the rear as well as pads for all around. There is some slight grooving in the front rotors and I'll measure them to see if they are "turnable", if not it will get new rotors. After seeing the sad shape the caliper was in I had planned on trying to snag a better pair at the 'yard Saturday.

Maybe I'll switch into "wiring mode" and start the top engine rewiring process tomorrow...

Justin

[ctaylor738]

There are plenty of posts on getting the turn signals to stay engaged - do a search.

You basically remove the unit and file some metal to make the "shoulder" that holds the switch in the engaged position a little more pronounced. After your experiences with the engine, you will find it a simple and satisfying repair.

Enjoying your exploits and applauding your efforts to keep this old guy from the crusher.

I did a search and found the thread Peter mentioned, with the pics. I think I can handle that! I need a nice easy repair and instant gratification on SOMETHING to help readjust my attitude a bit.

Justin

[psfred]

Justin:

These aren't "domestic" calipers -- the piston is chrome plated, and the bore may be as well.

Speaking of pistons in calipers reminds me of the "wonderful" new composition pistons Chrysler used in the Aspen -- they got hot, shrank across the mouth, and stuck like crazy. Very hard to drive as the front end had considerable scrub raduis (unlike Benz, who when to a zero scrub front end in 1962!), so when you stepped on the brakes, the car dived HARD toward the side where the caliper worked. Factory recall, they put in steel pistons.

If there is a perceptible lip on the outer edge of the rotor, replace it. DB makes them fairly thin to reduce weight, so it's usually impossible to turn them flat -- by the time they are flat, they are too thin. New ones are about $60 for the fronts, $30 for the rears, so it's not worth fussing about. Front ones bolt on from the back (duh!) so you have to pull the hub, rears just slide on, the lug bolts hold them on. The rears also have the drum for the parking brake, so remember to clean the cosmoline off that, too when you put them on.

Rotors usually last three sets of pads.

Peter

Peter,

I already have the rear rotors and pads. Jacked up the rear this afternoon and found that maybe in the process of jacking the front up the nylon inserts in the rear swaybar endlinks sorta disintegrated and the endlinks fell off! Man, what next...

Are these nylon "cup" inserts available or does the entire link have to be replaced? I have seen the end links on-line but no bushings/cups yet.

I sure wish I knew exactly how many miles was on this as my 168k mile 83 Volvo Turbo had less wrong with it when I ressurected it. I have a feeling that the last few years of this poor 450's driving life were not happy ones.

I think I'll start on the wiring harness tomorrow, maybe I can build that without tearing something else up!

I did crank it up a couple times today and it did seem to run much smoother (when cold) than it did yesterday and I did fix my turnsignal switch!


Justin B.

[psfred]

Justin:

I think the rear swaybar links were something like $18 each when I bought them for the W115. You have to buy the whole link, it bolts onto the wheel carrier and the swaybar.

Normal wear and tear -- take a look at the bushings on the swaybar to body mounts, and the ones up front, too, they are likely dead.

I've have to replace this stuff on the Volvo, too.

My 280 seems to get happier and happier as I drive it -- flew down the road today, seems to have more power, and it rides MUCH smoother now that I greased the front end again (something you won't miss on yours, you have ball joints instead of 14 grease fittings.....)

Peter

I found the swabar endlinks online for $13 and change/each, TRW brand. Just surious as to whether the bushings could be changed instead of the whole link.

Surprisingly the rubber bushings/mounts on the front and rear swaybars look surprisingly good.

I got the engine rewired today except for bundling the 1 million grounds together and coming up with a decent connector for the TPS. I suppose I can used individual terminals but a connector would be so much nicer. Unfortunately, all of the ones at the yard I've checked are brittle and/or the insulation on the wires is brittle. I hope it runs, sure was a mess of wire! But, all of the colors matched back up and I didn't have any wires left hanging so maybe I got lucky.

Justin B.

[psfred]

You did better than I did then -- I can't get one bolt loose on the starter, will have to get my brother on it, he's beefier than I am (and less fat, too). I could get both legs off the ground, but couldn't budge the bolt.

Naturally, I expect that I will find that the battery really is the problem and the starter is fine when I get it out....or that the engine is stuck or the ring gear shot (this week has had it moments!)

I did change an engine mount, since I had them and it was easy on the driver's side. Holy Cow, the engine sits at LEAST an inch higher, probably two! Should get rid of the vibration at idle and the rumble on acceleration! I will have to put the car up on jack stands in the garage to do the other one, I think I have to reach up and put the mount in from the bottom, cannot reach the upper bolt, its directly under the turbo.

Peter

I need to pull the starter out of this monster as well. It occasionally, about 1:3, will not engage. I got a new solenoid off e-Bay so will clean up the starter and put in the new solenoid someday.

Justin