The Murphy Builders Site

Went flying last night and when I landed at home, I noticed my left brake felt a little soft. No fluid eaking anywhere so I am assuming the O-rings in the master cylinder are needing replacement. WHile looking for the rebuild kit, I noticed that Matco has an 'intensifier kit' that supposedly increases pressure by 60%. Having installed 29" Bushwheels, a little more braking force would be nice.

Has anyone installed the intensifier kit in their Matco MC-4A master cylinders? Asking your opinion on what you experienced for improved braking and if the modification was much better.

That looks like a smaller cylinder and piston kit to get higher pressure. Let us know the results if you try it, if it works I'll be ordering a set.

Sorry for the delay in posting. I don't check in often enough.

Yes, I installed and intensifier kit for the same reason. Big tires.

The intesifier mod for my Matco cylinders really helped with my Alaska Bushwheel 29", 26" and 1800 amphib floats (with tiny brake discs).

BUT.

The installation was painful. Matco has sloppy tolerances and installing the parts was especially difficult with one cylinder. There are two serious but related problems with the installation. It is very difficult to bleed the brakes. With the normal Murphy setup, I would push brake fluid up from the wheels back to the reservoir. Sloppy (me) but easy. Impossilbe with the intensifier. With huge amounts of time and two people (my wife), we had to pump the brakes and push fluid down to the wheels to bleed.

But, the really bad problem is that these intensifiers do not let fluid flow back to the reservoir during normal heating and cooling sitting in a hangar. Any temperture swing over pressurizes the brake lines and the only release is by the o-ring in the brake puck. You drip brake fluid on the hangar floor, and worse, on the brake pads and rotors. Your braking goes to hell.

That is my experience. I never talked to Matco. I think they are a good company. Vans uses them for their kits. Check with them first. But I removed my intensifiers and all my problems went away.

Eric Foglein
N645EJ Tailwheel 6.00x6, 29", 26" and 1800 Amphib

I talked to Matco about the intensifiers a couple of years ago, and he strongly advised me to not use them.

Thanks for the replies everyone...albiet a bit late. Since I hadn't gotten any response I went ahead and ordered them. I guess they aren't all they are advertised to be. :( I did have a couple of guys on the backcountry pilot say they worked great for them, but I don't have any idea what kind of plane they were installed on.

Since they are on their way, I will try them and hope for the best.

PS. Curtis, my hangar is a 'Pole building' type. Being in northern MN were we get a fair amount of snow, it has held up well so far, for the past 25 years.

Totally forgot about this post.

I installed the intensifiers several weeks ago. Wasn't difficult, but was time consuming to gat a perfect fit. If not nearly perfectly fit, they won't work like they should. I had no problems with bleeding them from the bottom as I normally do.

As for improvement, yes, there is slightly more braking .