Brakes on a 450SEL - PeachParts Mercedes-Benz Forum

ptoro01 · #1 07-11-2004, 02:02 AM

For some late night thinking ideas that come to mind....If I had the funds to upgrade the brakes on my 450SEL, is there a simple transplant to do off another car. Is the whole setup off a w126 transferable. I am asking this because of 2 main reasons. I am planning on putting the engine out of a 560 into my 450 along with a 4 speed tranny to reach a new level of fun, for this, I also need the stopping power of great brakes. The brakes on there are great until the fade can be felt in the pedal and after that they are dangerous and scary. With a stronger engine, my intuition tells me that I will be even stupider on the roads and will need greater stopping power. #2 is that I would like to put some wheels on there with a 35mm offset without using spacers.

Just off the top of your head give me an opinion

thanks everyone,

Peter

psfred · #2 07-11-2004, 06:39 PM

Peter:

The brakes off a W126 chassis are nearly identical to the ones you currently have, it they in fact are not. You are unlikely to go faster with the 560, so you don't need "more"
brakes, just ones that work correctly.

"fade" on disk brakes is almost always a bad master cylinder or water in the brake fluid, so I would find out what's wrong and fix it before attempting to replace the calipers.

Personally, I feel that car is old enough to benefit from caliper and master cylinder rebuilds, new brake lines, and new fluid. Should clear up your problems, along with new rotors and pads. Sticking calipers, under-thickness rotors, and aftermarket pads can give you the symptoms very similar to "fade" -- hard (or soft) pedal under hard braking with inadequate stopping power.

I've never felt the MB had inadequate brakes, quite the opposite -- no other car I've ever driven has the same stopping power!

Peter

ptoro01 · #3 07-11-2004, 10:50 PM

Peter,

Thanks for the advice that I should go ahead and rebuild the whole system. I am planning on doing that once the engine is out this fall.

The fade I am experiencing is under extreme circumstances. I have bad driving habits and am way too aggressive on both pedals. I must agree that a rebuilding of everything is appropriate on a car that sat for 4 years and is now 26 years old. I was mostly looking to change the offset from the 25mm to 35mm to be able to use a specific type of rims without spacers. I dont quite understand the system but I have heard of nasty things about spacers.

Compared to a 560SEL, the transplant of the engine would give me a faster acceleration, a 4 speed tranny and better gas consumption. Since the w116 chasis is lighter than the w126, it would be considerably faster as well, until the higher rear end gear ration limits the top speed. Hopefully the estimations of a 0-60 in about 7 seconds with a top speed of about 120mph.

Thanks for the advice,
Peter

fahrgewehr2 · #4 07-11-2004, 11:12 PM

Hi ptoro01,

If it were my project, I would be looking at rest-of-the-world 4.5 liter motors. in k jet form, the hotter engine puts out 225hp, which is 45 more than your current setup. would swap in easier, I would imagine.

After all this, why not buy a 6.9?

Quote:

With a stronger engine, my intuition tells me that I will be even stupider on the roads

Maybe transplant the airbags out of that 560, as well?

ptoro01 · #5 07-12-2004, 02:34 PM

Hey fahrgewehr2,

I think that the 560 is a straight drop in.

The reason why I believe a 560 transplant could be the easiest is because I will be on the lookout to buy a 560SEL to part out when the time comes. Most likely, here in toronto, I will be able to find one that has been rear ended. I could take the engine out of that and the tranny along with many little things that might fit with slight adjustment. My seats are torn up completely, and I might want to take the time to fit those newer seats and hook up the controls to those. I much more prefer the doorpanels from a W126 as well and if I am extremely lucky, those could fit in a w116 allowing me to use the seat controls without much fabrication.

The airbag is a great idea. Not only from a safety point of view but because the steering wheel was taken from a semi. Although it does fit the car proportionally, I still think its huge. I havent thought about how the airbags could be put in and to tell you the truth they kinda freak me out. I will trust it if someone certified puts them in, but cruising along at 80 and a short occurs or the sensor jams I dont wanna be hit by an airbag for no reason.

The newer technology and much simpler setup of a 560 compared to a 6.9 is why I decided not to try to put that amazing engine in. I bought the car to restore and modify and I wouldnt touch it if it were a 6.9. I really love the w116s so hopefully one day Ill get to have the fast and modernized 560SEL w116 chassis and a stock, grampa style 6.9 with a nardi wheel.

Peter

psfred · #6 07-12-2004, 11:50 PM

Peter:

The only thing from a W126 that is going to fit a W116 chassis is the drive train -- the body is completely different and none of the parts will interchange. Save yourself the trouble.

Do not attempt to change the wheel offset (you cannot, anyway) -- it is determined by the "kingpin inclination" -- actually in this case the line between the upper and lower ball joints since Benz stopped using kingpins in 1973. You currently have a zero offset front suspension, meaning that the line between the ball joints will intersect the ground in the center of the tire tread, the ideal location. Any change will cause deterioration of handling performance.

You need to buy whatever wheels you want with the correct offset -- most manufacturers make their popular wheels in several offsets to fit a variety of cars. Changes in offset can radically change the handling (almost always for the worse), so stick with the factory spec. Note that Benz uses more than "normal", so that the tire is farther toward the centerline than is typical of most US design.

The only time disk brakes show fade is when the linings start to burn, a situation I would not expect in street driving, even with "bad" habits (that I strongly suggest you correct -- excessively hard driving leads to accidents and extreme wear on the car!). If the brake fluid has not been changed in the last two years, flush out the old stuff with new fluid, this will likely cure the loss of braking under hard use, since what you think is brake fade is probably boiling brake fluid.

If you have K-Jet, the 560 is easy except for the computer (you will need to transplant the wiring harness and associated bits with computer or it won't run right), but if you have D-Jet, it's a bit more complicated. You will need to replace the fuel lines with steel or some other high pressure line along with the fuel pump and accumulator, the D-Jet uses lower pressure.

Peter

WANT '71 280SEL · #7 07-14-2004, 01:31 AM

ptoro, My 116 has WAY more than adequate brakes. I have gone from 100-0 many times, VERY quickly, with no fade. My calipers were all replaced in '98, and the fluid has always been regularly flushed, so my brakes are as close to new as I'm going to get. I noticed once, after very hard driving (was in a hurry) that I could barely smell the brakes. That isn't uncommon to smell the horrendous odor.
Thanks
David

wbain5280 · #8 07-14-2004, 07:06 AM

Look at putting the brakes from a 6.9 on your car, vented front and rear.

What kind of brake pads are you using?

ptoro01 · #9 07-14-2004, 03:11 PM

Thanks for all the advice. I think I will go ahead and rebuild the system. I will also flush out the brake fluid and see how much that all helps. The car does stop on a dime, the only few times I could feel fade is when I was going from 100mph to stop a few times in a row or an hour or so of fast mountain driving.

psfred- You mentioned the k-jet and d-jet. How can I tell which I have. Also, replacing the lines shouldnt be as much of an issue since I will have the fuel pump and accumulator from the w126 that I could incorporate. Thanks for the info on how the suspension is all setup.

But Im still trying to figure out what needs to be done and the conversion wouldnt happen until november at the earliest.

Peter

psfred · #10 07-14-2004, 09:49 PM

K-Jet has a fuel distributor behind the throttle body with a steel in to each cylinder. D-Jet has an electrically operated injector with a fuel ring main around the engine and a temp sensor in the air horn.

Peter

grimgaunt · #11 07-14-2004, 11:05 PM

what is this rubbish about the door panels from a 126 swapping into a 116 body ?

If the drugs are THAT good please share

fahrgewehr2 · #12 07-14-2004, 11:14 PM

Quote:

The airbag is a great idea. Not only from a safety point of view but because the steering wheel was taken from a semi.

It was actualy meant to be a joke...it would be nearly impossible. The reason the steering wheel is large is so that the driver is kept in place in the event of an accident. Also, with power steering an option on some models, a large wheel was needed to provide enough leverage.

If you want 560sel power, airbags, door panels, brakes, power seats and steering wheel etc, what do you want to keep from your 450? Maybe you own the wrong car?

ptoro01 · #13 07-16-2004, 10:11 PM

Lol I so get your point. I love the vintage look and the design of the car. I would love to own a 560SEC but this is my project right now.

Although, with the lines of the car, I want all the mods to be suttle. You have to understand that this car was bought for $800 bucks. The interior was mostly gone and needed replacing, it had tons of little problems. Mechanically it runs so strong and amazing especially once I replace the clutch fan on it.

Since the car isnt a to-be collectible, I have decided to modify it with slight upgrades. I want everything to be suttle to some point. I want a 560 in there because I figure that I could rebuild most of the components in the engine bay that have rebuilding kits and do some crazy preventive maintenance. This way, I will have a car that is reliable and I trust it to be. Once I realized that these engines just swap fairly easily, and is way worth it I have decided to work towards that point. Also since the car is lighter, it will feel even more powerful.

Slight modifications to be practical such as the doorpanels would be for the enchanced functionality and woodtrim. The idea of power seats and the doorpanels go together so that I can mount the controls easier. The steering wheel, even if I just put a non live air bag and reduce the size of the steering wheel, it would still enchance the look and comfort. I always end up holding the wheel in the middle, right on top of the horn switch. Brakes I asked since the 126 is a heavier car and there might be an easy swap that someone knew of.

With the paint job needed, I have also decided to monotone most of the car and soon lose all the real chrome. All the polished aluminum is getting painted over. I will try to finally post some pictures soon of the unfinished product.

psfred · #14 07-16-2004, 10:20 PM

Weight difference between those models is minimal -- about 3800 lbs empty, just like the W108. German cars haven't changed size over the last 50 years, unlike American ones.

You will have fits attempting to paint over polished aluminum, nothing is gonna want to stick.

Peter

ptoro01 · #15 07-16-2004, 10:40 PM

Psfred, I have already painted most of it already. Before the car goes in for the actual paint job, I will have to retouch some little things all over the car that I missed and that will be it. I sanded down the polished aluminum a little bit before painting with etching spay. That stuck to it on the first try and hasnt chipped in 2 month of having it painted that way. It was detail work but it was well worth it. I strongly disliked the shiny especially around the windshield and rear window. Now it without it, the look is impressive and doesnt have the in-your-face I was an expensive car with lots of shiny parts on me anymore. I dont know why they lost most of the shiny on the 126s but they did a great without it.

I believe the difference was about 500 pounds if I remember correctly. The suspension is shot as well, and I am trying to figure out how to lower it and make it feel more sporty. I have found that all the parts for the rear will fit from a 126 and I am trying to see which if anything from bilstein and eibach will directly fit. The car is already very stable and had a firm suspension but with that upgrade and wider and bigger tires & rims, that will help it move quickly through corners.