On my 1994 Mercedes E320 wagon,I was trying to installed the replacement brake master cylinder. One of the two bracket are giving me a fit that holds the bottom of the ASR pre-charge box/part due to limited space. As a result of wiggling the brake master cylinder and the bottom bracket, the push rod inside the brake booster came loose. I read somewhere just put the push-rod into the master cylinder, and installed the master cylinder like normally would. It seems to have worked.

If that is the case, then I assume that the person who did this saying he does not know if it supposed to be permanently attached somehow or not. He also indicated that the pressure between the booster and the brake master cyclinder should keep it in place.

Any truth to that? Comments, advice, feedback is greatly appreciated.

IMO you are good to go. How are the brakes now, any better?

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Hi Sugar Bear, good to hear from you. No, I am still trying and working on the darn bracket that support the bottom of the ASR pre-pump box and at the same time putting in the master cylinder. There hardly any wriggling room trying to put in the darn asr pre-pump box inside the bracket that supported it. Is there a way to make more room/space by removing asr box from its connectors, hoses, etc., so I can put in the bracket along with master cylinder at the same time?

The problem is the bracket that support the bottom of the asr pre-pump box below the brake master cylinder is hard to put in due to limited space/room and juggling between the bracket and the brake master cylinder at the same time. Noticed on the push rod, there is a washer-type ring that has "teeth" on the outside of the ring. Does it matter whether or not when putting in the push rod inside the brake master cylinder and install the brake master cylinder to the brake booster affected the possibly alignment "teeth" of the ring inside the brake booster or just snapped on without damaging the brake booster and/or the washer-type ring with the push rod inside?

Sorry no advice to offer about the bracket. About the rod, if there are splines you should be able to rotate the rod slowly while pushing it toward the booster and feel it jump into position.

Good luck!!!

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Hey Sugar Bear, excellent last post, especially the word spline as I was trying to describe the push rod "teeth". Basically, try to line up the spline push rod in its place inside the brake booster and should be able to hear a pop or click sound meaning the push rod is in its place and good to go, correct? A long needle nose pliers on the push rod to push it inside the brake booster to make it work, since there is no room to push the push rod inside in the brake booster hole using by hand. I think using long needle nose pliers with vise grip should do the trick. Comments, anyone?

Sugar Bear, the splines on the washer type ring is rather loose with the push rod inside. How to rotate the ring with splines while it is loose?

Found this

https://www.pelicanparts.com/techarticles/Mercedes-W124/83-BRAKE-Brake_Booster_Replacement/83-BRAKE-Brake_Booster_Replacement.htm

it discusses the rod perhaps it will help. Try to use a cell phone to get pictures of inside the booster to see what you are working with.

Good luck!!!

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Sugar Bear, I read that DIY article Brake Booster. I scrolled down to the comments section. Yep, there were quite a few issues regarding with push rod out of the brake booster. I will check it out to see if any of the methods/ suggestions it would work. I will also try to get a picture of the inside brake booster tomorrow and put it on this post. Stay tune.

It would be best to access a factory manual to know for certain about the rod position if you cannot determine it for sure.

Hopefully a forum member has access to a manul and can look it up.

Good luck!!!

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Sugar Bear, I was going to send a picture of the inside brake booster today. However, today is cloudy and cold outside. Will send a picture when the day is warmer and lots of sunshine!

Sugar Bear, here are the pictures that I took them today. Sorry about the quality of the pictures. Does these pictures help at all to put in the Brake booster splined rod correctly? If so, how to do it, even though the washer/ring is in free play, spinning around loose from the rod itself? Comments/feedback/advice is greatly appreciated from all those who read this post.

Attached Thumbnails

         

Picture #3 helps. I think the question in your situation is "Is the rod all the way in?" correct? This is how I'd try to figure it out, measure the depth all the way INTO the center of the female spline in picture #3 from the master cylinder mounting flange on the booster. Next measure the distance to the outer shoulder of the female spline in the booster to the master cylinder mounting flange on the booster (same place as previous measurement). The difference between the two measurements is the depth of the spline.

Put two marks on the pushrod, one for each depth measurement. If the rod goes into the first mark and stops the splines did not engage. If it goes into the second mark indicating longer depth it went into the female spline.

How to stop the splines from rotating...perhaps a piece of tape on the splines and pushrod full length lengthwise but only enough (1/4?) of the way on the splines to stop the rotation as you'll need to remove the tape when engagement begins. Watching the depth marks made earlier, once the splines just begin to engage remove the tape and continue to push and seat the splines. In theory the second/longer depth mark should now lineup with the master cylinder mounting flange on the booster.

As far as whether or not the pushrod should click or snap into place, I don't know and suggest you consult a factory manual for this entire procedure. I hope another member can provide that info to you.

Good luck!!!

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Sugar Bear, thank you for the tip in your last post. I will do this process as mentioed above. Did you read the post that I submitted "Mercedes/SMART WIS ASRA & EPC Dealer Service Repair Workshop Manual" since you also mentioned earlier about someone having this particular manual. So far, no one respond about that one. Would you know about that particular manual?

Sugar Bear, your post "I think the question in your situation is "Is the rod all the way in?" correct?" Yes, Yes, you got that right!!! Thanks for the wording correctly that I was trying to come up with. Great.