1969 280sl, sudden loss of brakes and will not shift

[cattledog]

Hi Everyone,
I am starting to drive my '69 280sl after several years of not running.   I started it early this week and took it for a short drive around my neighborhood, overall it ran pretty well.   Today I changed the oil and replaced the spark plugs and took it for another short drive and it ran more smoothly etc.  I also replaced the air filter.

Strangely though after parking in my driveway today and turning the car off, I returned to the vehicle to start it again and it had NO breaks and is stuck in park and will not shift out of park.   The shifter moves easily but it will not shift out of park.

Could a vacuum problem cause this?   What are a few things I can do to track down the cause on this?

Thank you,

Chris

[hkollan]

Hi,

Sounds like the transmission linkage has come apart. This is quite common and
has been previously discussed on several occasions.
See one of the threads here:

https://www.sl113.org/forums/index.php?topic=24963.msg178482#msg178482

Hans

[ejboyd5]

Transmission and brakes are separate issues. Please describe exactly what you mean by "no brakes."

[cattledog]

Hello Hans and Ejboyd5,

I thought maybe the brake and transmission systems might share a common vacuum source or other common factor that could cause both to fail at the same time.   Thanks for pointing out that the issues are separate.

After reading over the shift linkage bushing issue that Hans pointed out I think the "broken bushing" issue is the source of the inability to shift.   I remember hearing an odd (not loud) occasional rattle coming from  in the last 1/2 mile or so as I was driving home.   The rattle probably started right when the linkage came apart and it seemed to be coming from the area of the shifter (its an automatic in case I didn't mention that).     I think I can pickup a set of bushings and give that repair a try.   I will try to take some pictures as I do the work on this.

On the brakes, the pedal just goes straight to the floor.   Bit more info on that...   When I got home the right front (passenger) wheel brake was very hot and some of the oil stains on the back of the wheel were smoking a bit.  There are a few small hills on the short route that I drove and I suspect the right front brake caliper is stuck closed.   I also noticed that the car was pulling slightly to the right when I drove it the last time.

I checked a few things this morning.    The transmission has enough fluid and it doesn't smell burnt at all so that's good.   The brake fluid reservoirs also have fluid but its kind of old!   I'm going to look under the car and look carefully for any leaks later this morning and see if I can find anything new and odd to report.    I did also notice the front of the brake master cylinder has a slight leak, at the seal where the assembly with the reservoirs is bolted on.   Not sure but I'm going to guess some air got into the system somewhere causing the brake problem.   With neither front or back brakes working at all would that suggest the master cylinder has a problem?

The troublesome thing is the car is stuck on my driveway now which is at a slight incline up until the garage.    With the back tires stuck due to inability to shift gears I have to figure out a way to safely move the car into the garage so I can work on it or have it towed to my mechanic.

On the bright side, I think I was lucky to get home safely with brake problem.  I guess I always had the emergency brake but not being able downshift with the brakes out would not have been good!   I never knew there was a problem until I went to re-start the car to move it into the garage after stopping briefly on the driveway!

Chris

[Jonny B]

As part of your getting the car back on the road, did you check the condition of the hoses for the brakes at each wheel? When a good friend of mine was getting his car back on the road, he had a similar problem (and I think it was the right front also) - almost caught the darn thing on fire. It might be a good idea to change the brake hoses. You mentioned that the brake fluid looks pretty bad - it should be changed out every two years (we can get away with that here in SoCal with the dryer climate). I believe we also changed out the master cylinder. These are not difficult jobs.

If you need a hand, give a shout, we are in North County.

[neelyrc]

.... It might be a good idea to change the brake hoses.

I agree Jonny B.  The front right hose is probably collapsed inside.  Do change them all, not just the one that appears to be the problem now.  The old brake fluid likely contributed to this problem.

[cattledog]

You guys are nudging me to not take the car into the mechanic with all this good advice!   

I looked under the car more carefully and there appears to be remnants of some burnt brake fluid on the passenger side front rim.   The stuff that's there is kind of sticky and not covered over with dust so I think its relatively new.  There isn't very much of this sticky stuff but something was definately leaking.  Jonny B, I will order replacement flexible hoses for the brake hoses.  I don't see any leaks around the existing flexible hoses but just seems smart to replace all the flexible brake hoses (thx neelyrc).    Pretty much everything that is (or was) "flexible" needs attention on this car!    Johnny B, I am in the Rancho Penasquitos area - I may take you up on asking for help if I get in over my head on this.

I'm going to pick up some wheel dollies from Harbor Freight then jack it up and have a go at pushing it into the garage.

The other thing I notice is that the carpet seems to be glued down on the transmission hump.   I think I can get a corner up and carefully pry it up to get at the bolts.

I also see a leak at the front of the master brake cylinder - I suppose air could be entering the brake system at that point.

At least most of the mechanical things are somewhat accessible in these older cars.   Can't say that for some of my newer vehicles!

I will post an update after I get a little further.

Chris

[kampala]

Cattledog,

you can temporarily twist a wire to hold the linkage together while you wait for the bushing,  This will allow you to change the gear so you can move the car.   Block the wheels while you do this.    My car was stuck on the driveway blocking the sidewalk so I used some wire and twisted it together.   

The reason to change the brake hoses at each wheel as Ralph mentioned is that fluid flows through the hose to the caliper when under pressure from pressing the brake, but when you let off, the fluid does not flow back since the hose is swollen on the inside and there is no pressure to push it back.   Common old hose problem.

[cattledog]

Thank you Kampala.   I plan to move the car into the garage after work tomorrow.   For now my plan is to use a dolly under each wheel.   I want to take my time opening up the gear shifter mainly because the carpet is glued down on top of the transmission hump and will need to be removed carefully.

You guys have a suggestion on where to buy the brake hoses and the linkage bushings?  My main concern is getting the right items.    I like using OEM stuff when possible.

Also the master cylinder has a leak at the front at the seal, where the reservoir assembly is bolted on.  Overall the cylinder has very little rust on it but it definately has a leak.   Any thoughts on whether I should plan to replace it or is it sometimes possible to just put a new gasket in and reseal successfully?   I'm suspicious that the cylinder has a problem since neither the front or rear brakes are working right now.


Thanks,

Chris

[JamesL]

Given where you are, I'd give the Classic Center up in Irvine a call about hoses, clamps etc
They'll have them

[waltklatt]

You mentioned a slight incline from your garage.
Do some planning on this with a way to arrest the backward movement of the car, if putting on dollies.
Careful there!
Walter

[cattledog]

Thanks Waltklatt,
I gave the dolly idea some more thought and ended up calling a tow truck instead, exactly for the "incline" reason you mentioned.   The tow truck had this really neat apparatus on the back that was able to pick up the back of the car by its tires and gently move it into my garage.   

Going to order some of the parts I need for the repairs this evening.

Chris

[Sleek Lemur]

Hi Cattledog,
Re the transmission linkage, I had exactly the same thing happen the other week, but on the way back to London from Italy... Pulled up the carpet and obviously the linkage had failed under the shifter. Managed to operate the actuating arm though, which got me home. Have repaired it fully now. Part was £3.57 ! The SL Shop did advise to replace the bush at the other end, too (under the car) as this is likely to be on the way out too (another £3.57 !). Easy job. I now have all by brakes jammed on (that goodness got home after 2,200 mile trip!). I suspect the master cylinder, as it's affecting all wheels. Though other members suspect the Vacuum Booster. At £139 for the master cylinder, worth replacing it after 47 years anyway. 

[cattledog]

Thanks again for all the help.   I am getting ready to lift up the carpet around the shifter.   What sort of glue would you guys recommend for putting the carpet back down?   I don't want to use something so strong that it makes it impossible to remove again in the future.

I ordered the replacement brake lines today - looking forward to getting them installed.

Chris

[cattledog]

Back again - turning into a bit of a pest here...

Does this look like the correct shift bushing part?
http://www.ebay.com/itm/161897086730?ul_noapp=true

Chris

[kampala]

As someone else mentioned - call the Mercedes Classics Center in Irvine.  You are dealing with small $ parts and this way you will get exactly what you need.   Call Tom Hanson and he will get it out to you immediately.  With you car info, Tom will help get you the right parts.  He will even give you a discount if you mention this site. Often prices are less than non-dealers for such parts and you will get what you need. 

good luck.

[Jonny B]

I would agree with my esteemed friend Oz. Get this from the Classic Center (you can even order it through you local MB dealer) I have ordered various hoses and standard kinds of parts through MB Escondido, with very quick delivery and reasonable pricing. If you are a MB Club of America member, the dealer will extend a 10% discount.

As for the carpet, I would not bother to reglue it. It should fit right into place with no issue.

[Tyler S]

If you are a MB Club of America member, the dealer will extend a 10% discount.

I have also had good luck getting 10% off stating I am a Pagoda sl113 member. Mercedes Benz of Monterey extends this discount to Pagoda group members. And they ship directly to you. Usually next day UPS

[Sleek Lemur]

Bushes are £3.57 from the SL Shop in England !

I wish I'd thought to not glue the carpet back....it did get slightly damaged when I took it up for the repair. Oh well, should be ok for another 47 years...

Am also going to replace the bush underneath. More awkward to get to but looks easier to replace !

[cattledog]

Hello there,
I have slowly been making progress with my repairs.  My next task will be to pull the shifter assembly out so I can try to install the new bushing.   You think the special tool that mercedes source is a necessity for this job?   

The tool looks like this,
http://www.peachparts.com/shopforum/attachments/diesel-discussion/121941d1401590089-shifter-bushing-tool-problems-fix-1985-300d-transmission-bushing-tool-ktc.jpg

If the tool can save me at least 30 minutes or prevent other problems I would like order one.

Chris

[cattledog]

Hello,
I removed my shifter from inside the car and found that the bushing on the control arm end nearest to the shifting lever was fine, it was the bushing on the far end of the shifter assembly, down by the transmission that had broken.    I was able to remove the remnants of the old bushing easily by cutting it apart with a packing knife.   After this, I threw the new bushing and the end of the control arm into a pot of boiling water.   After fishing the bushing and the control arm out of the boiling water I was able to insert the bushing pretty easily just with my hands while wearing gloves.   I didn't need the special tool after all; although I can see where that tool would still be useful if access was poor.

As for the brakes, I have replaced my flexible hoses and the master cylinder already.   It looks like one of the pistons in my right front caliper was leaking so I'm going to replace both front calipers.

I'm really excited to get back on the road - hopefully no other last second problems will pop up after I install the new calipers and bleed the system.

Chris

[kampala]

Nice to read you resolved the shift bushing issue.    The ATE rebuilt calipers are readily available even at your local Oreilly / Napa etc.  Due to not wanting to ship heavy cores etc, I got one locally and it was an original original ATE and worked nicely, about $60 if you give them your old core.   

Best of luck. 

[cattledog]

Kampala,
Would be awesome if I could find the calipers locally.   I had given up on that idea after checking with Napa and they did not have any and said they couldn't order them either.    Maybe the guy that helped me made a mistake...

I will check with some other local sources and maybe give Napa another call too.

Chris

[cattledog]

I checked with O'Reilly and they have rebuilt front ATE calipers for $58 ea with free shipping from LA which should take one day.   My old calipers look pretty tired so it will be good to get new ones on there.  The rear calipers looked OK but I may replace them for now.

I'm trying to decide now whether to buy a pressure bleeder like this one,
https://www.amazon.com/gp/product/B000Q6SL2W/ref=ox_sc_act_title_6?ie=UTF8&psc=1&smid=A2IS69AN9A0OWP

Or can I use my hand held Mityvac to get everything bled properly?

Chris

[Jonny B]

Chris,

My friend Barry and I have been using a vacuum bleeder for a number of years. Each time, it is "This is probably the last go round." but after a bit of jiggling with the o-ring on the fluid canister, we have been able to make it work. It is simple to use and does the job.

We just finished a bleed of his clutch, and we did the brakes on his and my car earlier this summer.