Author Topic: BRAKE FLUID - ENGINE SMOKE?  (Read 29416 times)

keesing

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BRAKE FLUID - ENGINE SMOKE?
« on: June 24, 2007, 17:39:02 »
My '69 280SL recently developed a brake fluid leak (slow & steady), after a week of driving pedel gets spongy... in checking B/F reseviour is near bone dry! BUT... when I top-it-off, and pump the brakes to get them up - I get about 1/4 of a mile of thick grey smoke out the exhaust!!! Curious - any thoughts or similar experience?

1967 250SL Signal Red
1969 280SL "Tweety Bird Yellow"
1987 260E Charcoal

Bob G MN

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #1 on: June 24, 2007, 18:21:38 »
This is a problem my mechanic told me about.  The brake fluid can leak into the engine and cause smoke when you first start the motor.  It sounds like you have a more serious problem if you are loosing that much fluid.

Bob

jeffc280sl

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #2 on: June 24, 2007, 18:34:08 »
The engine provides a vacuum for the brake booster to assist in braking.  Your master cylinder appears to be leaking fluid which is is being sucked into the engine via the brake assist vacuum hose.

Jeff C.
1970 280SL 4-speed

keesing

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #3 on: June 24, 2007, 18:53:57 »
Is this an easy fix... or much more serious than I thought???

1967 250SL Signal Red
1969 280SL "Tweety Bird Yellow"
1987 260E Charcoal

jeffc280sl

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #4 on: June 24, 2007, 19:31:15 »
Changing the master cylinder is easy.  Hardest part is bleeding the brakes of air bubbles.  Do a search, there is tons of info on bleeding.  I don't know how long it has been leaking but you may want to change your spark plugs and clean out the brake booster as best you can.

Jeff C.
1970 280SL 4-speed

jameshoward

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #5 on: June 25, 2007, 02:58:43 »
Get or borrow a power bleeder and save your sanity (and more wear on the master cylinder). They use pressure air to suck the fluid through the brake lines from the bleed nipples as you go round in order - just make sure you keep the res topped up as you do it. Doing it manually is a massive pain in the behind. If, however, you do wish to spend a day regretting the fact you didn't by a power bleeder, don't forget to put a block under the brake pedal so it doesn't travel until it hits the floor as you pump it - if you don't you might over extend the range of movement in the cylinder and cause damage. Good luck.
James Howard
1966 LHD 230SL

graphic66

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #6 on: June 25, 2007, 07:16:19 »
Never had much luck bleeding with the Mity vac, it is a very handy tool to have though. Build one of these and you will never have a hard time bleeding again  http://www.bmw-m.net/TechProc/bleeder.htm

enochbell

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #7 on: June 25, 2007, 08:32:31 »
Graphic66,

I made one of these many years ago and have been thankful for how easy it makes the job of changing brake fluid, even with ABS.  once upon a time I worked for almost an entire day, with this Board's help, trying (unsuccessfully) to bleed my brakes.  Long story short, nothing worked until I made this handy tool.

A suggestion: the instructions suggest using RTV or some such adhesive to fill the slot in the threads of the plastic cap.  That did not work for me, instead I got a fat rubber gasket and cut it to fit the cap.  And no worries about finding the cap: I was surprised to find that a standard GM resevoir cap from NAPA fits my '64.  Go figure.

Best,
g

'64 230sl, fully sorted out...ooops, spoke too soon

graphic66

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #8 on: June 25, 2007, 14:51:32 »
Yes, enochbell, that tool is one handy unit. The cap on my 66' 230SL is the same on my Mercedes 78' U900 also, it's nice how mercedes stuck with a design that works. I use that bleeder all the time. It's a great storage container for brake fluid also. It makes a hard two person job a cake one person job. I pump up to 15 psi and just open the bleeders one at a time until clear fluid comes out.

hands_aus

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #9 on: June 28, 2007, 05:11:36 »
David, Greg,
I am building a power bleeder.
My question relates to using it...
Do you actually put brake fluid in the garden cylinder then pressurize and use OR do you just fill the MC reservoir, then pressurize and monitor the MC fluid level as you move around the wheels opening the bleeder nipples and topping up when necessary?

The latter method would be a lot cleaner....any thoughts?

Thanks

Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto
Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL #114, auto, ps , 717,717
best of the best

graphic66

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #10 on: June 28, 2007, 05:19:30 »
You put brake fluid in the garden pump. It fills the master cyl. as you bleed. If you put a short extension on the bottom of your cap, when you are done bleeding you release the pressure on your bleeder and the brake fluid siphons back into the bleeder to just the right level. I put some rags down just in case. I also tighten the cap just slightly with channellocks before bleeding. For storage I put a baggie over the cap with a bread bag tie holding it on, then put the cap and hose up higher than the bleeder to avoid siphoning while in storage.

66andBlue

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #11 on: June 28, 2007, 18:46:47 »
quote:
Originally posted by graphic66

Yes, enochbell, that tool is one handy unit. ...

graphic66 and 'g', I sincerely hope one of you will come to Blacklick next month and give a demonstration.  :)

Alfred
1966 blue 230SL automatic
Alfred
1964 230SL manual 4-speed 568H signal red
1966 230SL automatic 334G light blue (sold)
1968 280SL automatic (now 904G midnight blue)

hands_aus

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #12 on: June 29, 2007, 04:52:39 »
quote:
Originally posted by graphic66

You put brake fluid in the garden pump. It fills the master cyl. as you bleed. If you put a short extension on the bottom of your cap, when you are done bleeding you release the pressure on your bleeder and the brake fluid siphons back into the bleeder to just the right level. I put some rags down just in case. I also tighten the cap just slightly with channellocks before bleeding. For storage I put a baggie over the cap with a bread bag tie holding it on, then put the cap and hose up higher than the bleeder to avoid siphoning while in storage.


David,
I was thinking there would be air in the plastic tube which would be pumped into the reservoir.
Did you prime the plastic tube before connecting the cap to the reservoir?
If not, what happens to the air in the tube?
thanks


Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto
Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL #114, auto, ps , 717,717
best of the best

graphic66

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #13 on: June 29, 2007, 06:16:26 »
Good questin, Rob. I never really noticed what happens to the air in the tube or the air pocket in the master cylinder. It has never presented a problem. It may just compress into a pocket at the top of the master cyl. and never enter the brake lines. Whatever happens, one thing is for sure, the brakes get bleed and the girlfriend, well what used to be the girlfriend before her Peacock attack, gets to cook dinner instead of pumping a brake pedal. It seems to, for some reason make the significant other iratible to sit in the car and pump the brakes.

Naj ✝︎

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #14 on: June 29, 2007, 06:50:21 »
quote:
Originally posted by 66andBlue

quote:
Originally posted by graphic66

Yes, enochbell, that tool is one handy unit. ...

graphic66 and 'g', I sincerely hope one of you will come to Blacklick next month and give a demonstration.  :)

Alfred
1966 blue 230SL automatic



I hope to get one of the pumps while I'm over 'there'.
I hope the local attendees will know where to get the rest of the bits, so we can try it.

naj

68 280SL
« Last Edit: June 29, 2007, 07:12:47 by naj »
68 280SL

jeffc280sl

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #15 on: June 29, 2007, 06:52:58 »
Don't forget about the effect of gravity on the brake fluid and air.  As long as the volume of air in the master cylinder (combination of original vacant space and that from the pressure bleeder tube) does not exceed that of the master cylinder chamber you will not pump air into the brake system.  As you begin the process a small volume of air from the tube will be pumped into the master cylinder chamber followed immediately by fresh brake fluid.  The weight of the brake fluid will go to the bottom of the chamber and the air will set on top.

Jeff C.
1970 280SL 4-speed

Peter van Es

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #16 on: June 29, 2007, 09:17:56 »
quote:
Originally posted by graphic66

Good questin, Rob. I never really noticed what happens to the air in the tube or the air pocket in the master cylinder. It has never presented a problem. It may just compress into a pocket at the top of the master cyl. and never enter the brake lines. Whatever happens, one thing is for sure, the brakes get bleed and the girlfriend, well what used to be the girlfriend before her Peacock attack, gets to cook dinner instead of pumping a brake pedal. It seems to, for some reason make the significant other iratible to sit in the car and pump the brakes.



Dear Graphic...

Here's my famous Peacock Recipe. If you are as good with kitchen utensils as you are with brake bleeders, this should put equilibrium back into your relationship (I mean, you can get even...)

Redressed Peacocks which Seem Living; and How to Make them Breathe Fire through their Mouth - from Cuoco Napoletano:

You should first kill the peacock with a feather, driving it upon its head, or else drain its blood from under its throat as with a pig; but it is better to take out its tongue and then to slice it under its body - that is, from the top of its breast to its tail - slicing only the skin and removing it gently so that it is not damaged; when you have skinned it, pull the skin back right up to the head, then cut away the head, which will remain attached to the skin; do the same with the legs, and likewise the tail, taking out the leg bones so that the iron will make the peacock stand up will not be seen; then take the skinned carcass and set it to roast stuck with lardoons, or else baste it with grease often enough that it will not burn, and stick it with whole cloves, and fill it with the Piglet stuffing but without garlic; cook it gently so its neck does not burn; if the neck should get too much heat, cover it with a damp cloth; when it is cooked, take it down and redress it in its skin, whose inside you have coated with spices, salt and cinnamon. Then, when you have put its skin back on, get an apparatus of iron driven into a large cutting board and shove this iron through its feet and legs so it cannot be seen; in this way the peacock will be standing so that it will seem to be alive.

And to make it breathe fire through its mouth, get a little camphor with a little fine cotton-wool around it and put this into the peacock's beak and soak it with a little aqauvita or else with a little fumey old wine that is volatile; when you want to serve it, set fire to the cotton-wool: in this way it will breathe fire for a long time. To make it more magnificent you can cover the peacock with gold leaf and then cover it with its skin.

The same can be done with pheasants, cranes, geese and other birds.

Scully, Terence. Cuoco Napoletano. The Neapolitan Recipe Collection : (New York, Pierpont Morgan Library, MS Buhler, 19) : A Critical Edition and English Translation. Ann Arbor: The University of Michigan Press, 2000.

Who said cooking was easy?

Peter

Check out http://bali.esweb.nl for photographs of classic car events and my 1970 280 SL
1970 280SL. System Admin of the site. Please do not mail or PM me questions on Pagoda's... I'm not likely to know the answer.  Please post on the forum instead!

hands_aus

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #17 on: July 01, 2007, 05:23:51 »
Hey JeffC and graphic66

Thanks for your responses.
I have noted the info for when I do the job.

Did you guys add a pressure gauge to the unit?

Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto
Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL #114, auto, ps , 717,717
best of the best

graphic66

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Re: BRAKE FLUID - ENGINE SMOKE?
« Reply #18 on: July 01, 2007, 07:59:20 »
Yes I put a pressure gauge on it. It was a dial gauge for low pressure tires. I pump it up to 15 PSI.