Brake Problem and Missing Heat Shield

[Amanda]

First issue popped up with the new baby.  Took it to see the mechanic and one of the brakes "stuck" after hard braking.  After it had a chance to cool down, it unstuck and was ok on the ride home.  I found this link

http://index.php?topic=5622,Problems

Do I understand this correctly - that the two main causes of a sticking brake would be bad hoses or a bad caliper?

The other main issue was a missing heat shield - we did notice the floor getting pretty hot, so hopefully replacing that will help.  Otherwise he gave it a pretty clean bill of health!  And I learned that having the oil pressure gauge all the way at the top is a good thing - phew  

Amanda
1966 230SL
Manual
Red/Tan
Los Angeles

[al_lieffring]

To find out if the problem is with the hoses or the calipers, check to see if the pistons will retract freely with a pair of channel lock pliars. If one of the pistons won't retract, open the brake bleeder, if then the piston mooves freely it is the hose that is the problem. If it is still stuck with the bleeder open the caliper is the problem. In either case replace brake components in pairs. And if replacing the calipers, I would recomend replacing the hoses too.

Also if the brakes pulls to the left, look for the defective brake on the right side. and vise versa.

Before doing any brake work, loosten the cap on the brake fluid resivior and put a towel over it to catch any fluid that will overflow from the tank. Brake fluid will damage any paint that it comes in contact with.

Al

113-042-10-014715
built 11 Jan 66
904/396 blue, Ivory Tex
condition- rust bucket

[lurtch]

Hi Amanda - -

What happens with these older cars is that the rubber that is used to make the brake hoses begins to degrade. In technical terms,  the hose becomes permeable  instead of non-permeable. Then what actually happens is the inner diameter begins to get smaller and smaller as the hose material absorbs brake fluid. In the worst cases the hose will actually completely choke-off and not allow any of the brake fluid to flow back out of the caliper after the brakes have been applied. It sounds as thought that is what is happening on your car. This same thing happened to my car after I stepped on the brakes for the first time in five years.


Forget about further troubleshooting - -  I suggest you immediately order a set of new calipers and a set of front and rear hoses. You have probably already done so  - - EH?

Regards  - - and keep us informed?    Larry in CA    '66 230SL

Download Attachment: RRear-brake-hose.jpg
20.41 KB

[mdsalemi]

Hello Amanda,

Part of the challenges you will face, now and in the future, is when something goes wrong, to determine what if anything had been done in the past and when.

I'll agree with Lurtch here--you probably need to obtain rebuilt or new calipers (some offer them on exchange) and all new hoses and re-fit everything.  Don't forget the master cylinder as well.

Some call this "brute force" and abhor it as a waste; many prefer to do careful diagnosis and fix or repair things as needed.  But let me tell you--if one hose is bad, and they are all the same age, maybe as much as 30 years or more--how much longer do you think you have on those other hoses?  If one caliper is sticking and nobody can tell you if the brake fluid was changed religiously every year (as it is supposed to be, FYI)the OTHER caliper may give you trouble in short order.  Maybe not.  BUT, if you "do the brakes" as Lurtch suggested and I am putting in a good second motion here, that will be one thing you can scratch off your list.

As the brakes can save your life--and your car too, it isn't a bad idea to ensure they are all in tip top condition.

Regarding the heat shield, mine was missing once too, and we found one and installed it.  Didn't really appreciably change the amount of heat on my floor though--these cars run hot.

Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored

[rwmastel]

Amanda,

Good job searching the forum, I third the motion to get the brakes done.  I'm sure the hoses are bad and they don't cost much to replace.  The calipers can be examined to see if they are bad (rusted).

I see your new ride is a 230SL.  Do some searches for "oil fuel injector pump" or the like.  Your fuel injector pump (the mechanical one in the engine bay) has it's own oil resivoir and dip stick.  Please find threads on this and have it checked.

Also, there was a recent post about the "infamous" seal in the oil filter housing.  Someone had one that didn't fit as they expected.  Please search on "oil garden hose seal" or similar and learn about that.  Have that checked.

We all hope you're enjoying your Pagoda.  Treat it well, not only for your own pleasure, but because you're just a temporary costodian that's keeping it nice for the next owner many years down the line.

Thanks,

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[Amanda]

Thanks for the input.  I'm still very novice when it comes to the engine work, but I've found a mechanic I feel comfortable with, and he is going to work on the brakes.  We've also talked about replacing all the hoses that need it throughout the car as part of a more general tune-up.  I will ask him about the fuel injector pump.

The car does have some leaks, but they all seem to be of the "slow" variety - i.e. no drips.  We talked about steam cleaning (?) the engine to get a better idea of where the leak(s) are coming from.

Amanda
1966 230SL
Manual
Red/Tan
Los Angeles