Cracks and epoxy - PeachParts Mercedes-Benz Forum

psfred · #1 08-30-2002, 10:52 PM

We ground out the cracks in the block on the 280 SE 4.5 tonight and JB Welded them. Looks good so far, at least the epoxy stuck to everything. One large crack just under the cylinder head on each side and one small hairline crack half way down on the right side and a short one at the base of the valley on the left. The worst thing we ran into was that the block was still full of water. Anybody know where the drains are on the block, if there are any? I've some concern that one crack wasn't completely dry.

I'm going to let it sit until Monday unless it sagged through the wide spots when I check tomorrow, then pressurize and see what happens.

With any luck it will be driveable by the end of next week!

Peter

psfred · #2 09-02-2002, 09:15 PM

I put it all back together today. Runs fine (if you ignore the water leak at the water pump). PLENTY of power, almost scary.

I found the brake trouble (or at least the start of it, anyway) -- blown brake line at the right rear. I'm going to replace both hoses this week, no point in just doing one. Idiot PO left this go for a LONG time -- the paint and undercoat have all been eaten off everything from the line on back, starting to rust. Big pain to fix.

Water pump is also scheduled for this week, if I have time, since I cannot drive it anywhere until that gets fixed -- sprays water off the fan!

Any suggestions on what to use for a flush? The water is orange at the moment from not having coolant in the block for a couple years -- will the standard citric acid be adequate or should I use something a bit stronger?

Tranny seems fine, drives OK, but wanders a bit. I have new subframe mounts, will do them when I get a chance, maybe this weekend.

Peter

MikeTangas · #3 09-02-2002, 10:19 PM

The drains are on each side of the block, look like 19mm bolts. The driver's side is forward of the motor mount, passenger side is between the motor mount and starter (difficult to see until directly beneath it). Both will likely be tighter than all get out, then when removed nothing will flow. This is most likely due to a crud plug, just poke out carefully with a small screw driver or awl.

psfred · #4 09-02-2002, 10:49 PM

Thanks Mike!

It was difficult to see, since we were working outside in the dark (good planning, like usual). I'll probably try to pull them when I do the water pump.

Any thoughts on a flush program? I suspect this engine is filthy, and don't want to run with all sorts of junk in the cooling passages.

I sure is a gas to drive, though!

Peter

MikeTangas · #5 09-03-2002, 12:55 AM

Don't know about trying anything more caustic than citric flush. I'd probably just go for multiple citric flushes (like 2-3 x's), be sure to have the levers set to heat so the core drain as well. Not sure if you'd want to venture too far from a 50/50 mix when done, but out here in the desert area 40/60 and a bottle of Water Wetter keeps mine cool.

leathermang · #6 09-03-2002, 07:39 AM

Your best bet is to take the freeze plugs out... then get a small water blaster and a 90degree nozzle on it... stick it into the freeze plug holes and turn it all around and don't stop till you have only clear water flowing out... then do whatever flushes you want to do and it will actually be able to get to the metal in the corners...I have acquired cars which were completely full of what I assume were antifreeze crystals... light blue/clear crystals completely filling the cooling system...If I had not opened it up I would not have known they were there until it started to overheat from lack of water flow....

psfred · #7 09-03-2002, 09:43 PM

I started an EDTA flush (Zerex) tonight, will probably empty it tomorrow and add some more EDTA (I have a pound jar of it), the flush with clear water. There is a lot of rust floating around in there tonight, so it hasn't dissolved yet.

The car was very well maintained until three or four years ago, when the guy I bought if from started neglecting it. Leaving the block full of water (duh!) caused some corrosion, I'm sure.

Peter

psfred · #8 09-07-2002, 04:54 PM

Well, first flush is done, water pump is replaced (finally, what a pain) -- only had to replace on bolt that was siezed so badly we bent it getting it out.

The water pump has been replaced recently on this car -- whoever did it used blue silicone sealant on the gasket, so I know it wasn't my friend Hans, who knows better (I'm going to give him hard time about it anyway!). The water pump has been leaking for a long time, probably since installed (as pre usual with blue silicone sealant -- I learned this the hard was and not only use Permatex). Lots of soft corrosion/salt deposits, too.

The bad news is that I cannot finish the job -- the oil cooler bracket has come adrift on the bottom, so the rad has to go visit the radiator shop -- will probably have it cleaned while there, no reason not to. Had to replace all the belts, too -- old and hard, probably why the water pump was grinding (there was water slining off the fan all over the fenders -- not a minor leak!). Not bad except finding someplace that had two belts for the PS pump -- can't get matched pairs, either.

So here I sit, no rad. I also cannot find a way to properly tighten the power steering pump, either -- what is the secret? I can't pull it up enough by had to suit me, but can't find anyplace to pry against the brachet, either. Hints will be appreciated!

The engine mounts are so flat the left manifold is banging on the steering box and the right manifold is about to burn through the battery cable -- when my back recovers from yanking the rad, the mounts get changed. May be easier with a jack underneath to get some clearance.

The engine shocks are bent and stuck -- might explain the rough idle and noise, eh?

More fun every day!

Peter

skalie · #9 09-08-2002, 05:09 AM

Er, what's that about blue silicone sealant?

I sort of remember using a tube of blue stuff way back when to seal a thermostat housing. Thought it was gasket sealant or something, the instructions were in French, this was a mistake, peut etre?

dabenz · #10 09-08-2002, 10:42 AM

I'm not a chemist but my experience is that the silicone stuff doesn't do well in pressurized antifreeze systems. My miracle goop is Permatex No. 2. I use it wherever I need to help a gasket, help a taper thread seal, and even behind the flare for non-pressurized push on tube fittings when the flare gets nicked. Only drawback is waiting for the stuff to set (dry).

psfred · #11 09-08-2002, 11:33 AM

Blue silicone RTV sealant is advertized and sold to seal anything automotive, and it doesn't work for the following reasons -- it doesn't stick to anything with water or glycol on it (so unless the cooling system parts are brand new and very, very clean, it just sits on top) and it is isn't much more compatible with oil or detergent.

I've used it in the past and had terrible problems with leaks and disintegrating gaskets. When I returned to my old standby, aircraft Permatex (the liquid in a can with a brush), all the trouble went away. I always coat paper gaskets completely, especially the inner edges in contact with the coolant, after I had the gasket fail twice on the old Fox -- horrible place for the water pump, impossible to reach.

I also use antiseize on every bolt, steel to aluminum or steel to steel -- makes life MUCH easier the next time, and I know they are correctly tightened, not just stuck on dirty threads.

I may get greedy and solder my oil cooler suppert myself today and see if I can get Big Blue running -- I'm loosing patience!

Peter

psfred · #12 09-08-2002, 04:37 PM

Update on Big Blue:

Engine mounts are in, no real trouble once I jacked the engine up the couple inches it had fallen -- glad I did this with the rad out! The only trouble I had (other than getting a wrench on the bolt to get them out initially) was getting the left bolt back in -- had to get a pry bar and shove the engine over about half an inch to get the bolt to start.

Engine shocks were completely shot -- one had no reistance, the other cannot be moved -- unfortunately, the replacements I have aren't the correct ones, too long. Will return them tomorrow and also get new rubber mount pads, mine are all shot. May get new steel bits, too.

Also took the master cylinder off, will rebuild that this evening and replace it, then probably crawl under and do the rear brake lines (cross your fingers that I don't get a stuck fitting!).

The amount of oil and dirt on the right side is amazing -- either the valve cover leaks or Big Blue uses considerable oil and the PO wasn't too carefull about getting the bottle in the filler cap -- dirty oil half and inch thick.everywhere on that side.

Update again: Master cylinder is finished and installed. Very easy, just swap the guts. Looked fine inside, but the rubber parts were rock hard. I have a solid (sort of) pedal now. Also did one rear brake line, was leaking for sure, had blisters on it. No problem getting the line off except for brake fluid pouring all over me (yuck). Better pedal yet. I'll probably install the one on the other side if I can find it -- probably in my brother's car, since we took it along to get correct line wrenches the other day. Always something.

Aren't old cars fun?

Peter

MikeTangas · #13 09-09-2002, 11:55 AM

To tension the steering pump I used a piece of wood. Inserted the wood on the inside edge of the pump and pushed toward the right fender to tension, then tightened one bolt to hold. Be sure you don't get the pump belts too tight, causes premature wear to the pump bushing.

psfred · #14 09-09-2002, 07:09 PM

To say nothing of the water pump bearings, Mike! (probably the reason this car has had two water pumps in four years of driving!

Peter

MikeTangas · #15 09-09-2002, 07:14 PM

Yea, and the water pump too!