How Faithfully Do Mechanics Drain the Block?
 

As I've read up on the proper procedure for changing coolant (it's certainly clear according to the FSM that both the radiator and the block should be drained), I've been interested in two things:

1. The widely varying degrees of difficulty people have in freeing up the block drain....in the experience of some it's easy, for others it's been a nightmare. I must admit, the latter cases make me a bit reluctant to do it myself.

2. The inconsistency of professional mechanics (both indies and MB techs) as to whether or not they drain the block.

So I wonder: if you walked into your and and simply said, "Replace the coolant," would they drain the block? If not, why not? Laziness? Ignorance? Don't think it matters for some reason?

I expect a fully equipped shop has ways of flushing cooling systems we can't replicate in our driveways. This is the first I hear of using vacuum -

http://www.youtube.com/watch?v=-P98HrCl-G4

Sixto
87 300D

This guy needs to back to grammar school -

http://www.youtube.com/watch?v=VMyoyzowkJI&NR=1

Sixto
87 300D

In general I would think that on average when one of us does it to our own old MB it would be done more carefully and fully....

I agree, you cannot pay ANYONE enough to do a job well today, its all about time and money. Flushing takes time along with citric acid, etc but most shops will R&R and that's it. What is distressing to me is to pay a pro good bucks and then go back in months later and discover what they have forgotten or broke -pisses me off! Do it yourself and sleep well at night -my two cents, good luck

X2

That's why were here sharing information.

To do it right, might take 4 hours @ $75/hr shop time, plus materials and overhead. Would anyone b@#ch about a $350-$400 bill to "Change coolant, flush block"? I didn't think so.....

Sounds like it's almost guaranteed to be a unverisally-neglected procedure....virtually no one would pay several hours labor for a coolant change. Which also makes it a virtual certainty that my block drain plug has never been touched!

Next time you pay your mechanic for something and he has the car on the lift, get him to break loose the plug ( but not drain) on the block. Then take it home and DIY and take your sweet time about it.

Just because a business has a shingle hanging out that says "Mercedes Repair" doesn`t always means they know every little detail of every model. many shops are "All European Repair". meaning they are generalists.

Even going to the dealer doesn`t mean you are going to get the quality of service you would expect. these old MB`s we all own are far older than the majority of the mechanics working there.
I was 33 when the first 77 W123 was sold, and now 67. so the majority of the experienced are retired.
you may find some younger mechanics that have a passion for these old diesels, but they are probly far and few between.

I would bet the block drain plug would not be removed. shops are looking for the fastest way to get a car in and out and get to the next project. It is all about time and money. their time, and your money.

Most people wile rise to the level of their incompetance.



I removed the plug on my old engine in the 85 about 4 years ago, and as I remember, it came out w/o too much trouble.
I would say, "Just do it"

Charlie

If the issue is fluid renewal/purity, that can be easily achieved by multiple drains of the radiator. For most of us, that's easier (albeit slightly more expensive) than draining the block. So, realistically, what's the practical disadvantage of never draining the block? What degree of crud/sediement are we talking about here? What is it that eventually fails or is damaged if the block is never drained?

I don't have info for a MB but I see labor for a Chevy at 0.6hr to drain and fill and 1.5hr to replace thermostats, inspect system and flush.

It concerns me that the terms 'drain and fill' and 'flush' are used interchangeably in the service industry as in the videos linked above.

Sixto
87 300D