81 Seca XJ750R Master Cyl Resevoir plug?? cracked?? Help

Hello: Deborah newbie here.

Well I had the entire master cylinder apart, replaced the parts and found that the plug that connects the resevior to the master cylinder is worn and cracked.

I guess the part at present is unavailable.

Does anyone have any solutions on how they have handled this. I must not be the only one that has encountered this.

I thought maybe I could try and seal it up with some gasket sealer. I put the sealer in some brake fluid and it dissolved. I guess that won't work.

I tried looking on the net to see if I could find some type of brake fluid compatible sealant which I could not find. I guess most seals are by clamps and pressure.

What have other people done in this situation?

I thought maybe I could try and find a brake fluid compatible plug to fit in there or trim up something to fit. I talked to my instructor at school and he said the only alternative is to see if any dealers have some old parts stock or replace the master cylinder with a different type.

But in that case, I would have to replace the handlebars, switches and the brake lever assembly.

Would the Maxim set up fit on the Seca?

ANy suggestions would be appreciated.

Deborah

 

hi deborah, my first thought is you do not want to "patch" anything on your brake system. you are dealing with life and death here. your brakes should be the best operating / most reliable part of your bike. if i was you i would spend some time on ebay, or locate some bike salvage yards, if you want to save a little bit of money. or give up a fair chunk of change and get it from the dealership. unless i am missing something on your post, you should not have to consider replacing your complete handlebar assembly just for a part of the master cylinder. that's just my .02 please don't try to cut corners on your brake system though !!!!

 

Hi Scooter Bum:

As far as I know this part does not exist.

If I go to a salvage yard, its going to be the same, a 30 year old grommet that is cracked.

I'm just wanting to get some opinions from folks on replacing the system with the Maxim system.

I'm just trying to see what others have done and what has worked for them.

Thanks for your input. Yes I agree Brakes are important, but if something does not exist, improvisation or total replacement may be the answer.

 

I'm not sure what you are saying here?
Are you talking about the banjo bolt on the end on the brake line between the handle bar and the resevior?

 

Hi Hound:

On the 81 Seca XJ750, the master cylinder is wierd and it is located behind the headlight.

There is a plastic assembly that holds the diapgram and cover which holds the brake fluid. This is attached to the metal master cylinder assembly. There is a little plug that seals between the resevior and the metal part.

I'll see if I can download a couple of pictures.

Chacal does not have it yet. He said he is in the process of having it made, but several months down the road.

He indicated that the part is not available and that Yamaha never made it. It was a part of the master cylinder assembly.

 

Deb post those pics here so others can see what you're trying to accomplish.
What would hold up to brake fluid?
Possibly fuel line with a thick enough wall that you could sand to the right dimesion to fit the hole.
After market MC would solve the problem but they are exspensive.
You have already talked with Chacal he would know what would work.
As you already know the 750 Seca is unique in the MC department.
Sorry not much help.

 

Black RTV. The stuff Chacal sells with his master cylinder sight glass pieces. XJ4Ever part number HCP3120.

 

Hi Hound: I have email Chacal again to see if has another solution. I can't post the photos, the file is too big.

I went to the auto parts store and we tried brake hose, one end fits, the other is too big. Maybe I can get some different sizes and experiment.

It appears that we're just trying to prevent brake fluid from leaking out. The resevoir holds the fluid that flows into the master cylinder area.

I think the RTV may work.

My instructor at school does not think I should try anything, but what do the people in Brazil and South AMerica do. They make something and make it work.

I'm thinking if I could buy a new stock master cylinder, that may work, but I don't think you can buy them anymore.

In looking at the parts diagrams, it appears that the 81 750 Maxim uses the same size hoses and connection points, I would just need the adapter, the hose and the master cylinder and would just have to get another lever and control.

I don't want to cut corners or save money, but if Something does not exist, what do you do?

 

You're talking about a resevoir drain plug? Ok, I agree that brake systems are critical but I'm sure that you can come up with something safe that will work. It's good to hear that Chacal is working on a solution.

 

I would take your leaking part and head out to the motorcycle/car parts store. Some stores (at least the good ones) have a few good heads in them and they can look at various applications and see if there is something close that will work.

 

I've gone to the local auto parts store and they thought it would work the way it is. We also tried brake hose, but it was too big. It never leaked, it just has cracks. My instructor says we can put in back in, but it will eventually leak.

I just can't believe that on one has had this issue.

I will try the motorcycle shop. They'll just say, "buy a new bike".

 

I hesitate to mention it but I have a spare assembly in good condition. If worst case comes to pass, I will swap units with you as I can afford to wait a while for the new seal (would you cover the new part?). PM me for details.

 

Sure Robert: I cleaned the master cylinder and put a new re-built kit in it.
I will pay you ahead of time for the part if you want. Not sure how much he is going to charge for it.

I was just wondering if I could use the sealant to seal up the plug? the same type that Chacal sells for the brake fluid site glass window.

I would be willing to do that.

I sent a fax to several dealers and also sent emails to see if they have a new master cylinder sitting in their old parts inventory. You can't just buy the part, you have to buy the whole thing.

Maybe I should have got a Maxim???LOL

Thanks again.

 

I'd be very cautious about the brake sight glass sealant, I'm not sure if it is flexible enough. I suppose you could effectively glue the whole assembly together with the sealant but it would look rather hokey.

 

Hi Robert:

I doesn't show. SO it really wouldn't matter how it looks.

I spoke with a dealer and they said I could stop by and they could see if they have something that may work.

If I don't have any luck and if you are willing, I could trade you, but its up to you.

My school ends the third week in May, and I would like to have it all buttoned up and ready to ride by then.

Thanks,

Deborah

 

Hey guys--update-

I went to school tonight and we decided to change out the master cylinder to the handlebar mounted type.

I know I will have to make some mods to the handle switch and plastic, but will eventually change all that out I think.

Thanks again for all of your input.

Deborah