Brake Fluid Advice

Hey Guys.......Been out of touch since early May. Lots of video production work for the Army and the Navy at places where internet was mostly blocked. Anyway, now that we are back on the farm, we are doing a lot of catch up work that the live in hired hand didnt get done or just put off. </p>


One of the first things is doing the 2 year/200 hr service on the RTV. No real problem as it looks straight forward and in the owner's manual...........EXCEPT.......the brake fluid change out.</p>


Is this really necessary? I know on BMW motorcycles it really is important as the hydroscopic qualities of brake fluid will pull in the humidity like a sponge here in Georgia, pitting the cylinders and messing up the seals...................So.....if it is needing to be done............</p>


HOW.............????</p>


Havent really looked yet, but I imagine each wheel has a cylinder of some type with a drain.............attach a hose to each wheel, one at a time............pump, loosen the plug, pump and hold to floor, tighten plug, let pedal up, loosen plug, push pedal down, tighten, let pedal up.................on and on.............do this while monitoring the master cylinder, keeping it full, until each wheel pumps out fresh clean fluid.............</p>


I guess I hate to go through all of this if it really doesnt HAVE to be done................Thanks guys.........Dennis</p>

Hi D&D, I have never changed mine, but I do have the info for doing it. I finally broke down and bought a shop manual from the nice folks at Messicks. {I also got the parts manual.} I am sure that they will quickly pay for themselves . The manual says to use only DOT-3. It also states not to let the reservoir run completely empty during changing or the system will need to be airbled.It seems that you 1. jack up and remove front wheels 2. connect clear plastic hose to bleeder and other end into a container. 3 remove brake fluid reservior cap 4. fill reservoir with new bf 5. temporarily put cap back on 6. open bleeder . 7 pump brake pedal and hold it. 8 close bleeder and release brake pedal 9.repeat for other. 10 add fluid to upper level in reservoir. 11 after changing the fluid, check for proper function, 12 bleed air if necessary.IF the brakes feel spongy then they may have air in the line so will need to be bled before using. I believe this info to be correct but .... I have never done this. PM me if you would like the diagrams and I will see what I can do . I will check back tomorrowevening.Bordercollie</p>

Hey Border Collie and thanks.............by the way, do you raise them???.............we use a BC with our goats for herding and HE is the most fantastic dog I have ever had............another thread but oh my such a dog.........</p>


Yes, I understand the technique and totally understand the procedure...........What a pain in the tail to have to do.......I guess I am wondering if we really HAVE to do this..........Again, with motorcycles, specifically BMWs this is totally necessary.....Personal experience has burned me twice with a total rebuild of the master cyclinder and calipers. </p>


I guess I need to check out the location of the wheel cylinders and hope I dont have to pull the wheels to get acess to the bleeders to put the tube onto them..........What a pain.............So does one HAVE to do this????????.............Dennis</p>

Dennis I ride a Honda Valkyrie motorcycle that recommends a brake fluid change when the fluid starts to get white or "milky". The fluid is DOT4 which seems to absorb water faster - mine Vlk needs a change about every four years. The change of fluid on the 900 using DOT3 fluid seems to be excessive. The 900 is the first piece of equip,ment or motor vehicle that has ever stated a change every two years. I looked under my 900 but could not see a bleeder valve. Probably BC could enlighten us on where the "bleeder" valve is located. It would probably not be a big deal to change the fluid every few years. As much as I use my brakes I probably don't need to worry!!!!!!!!!!!!!! jd</p>

Hi Guys, According to my manual. ...... It shows the bleeder in two different places. In one picture, this bleeder is really close to the wheel{probably why they say to remove them} . Look on top of the axlein the 12 oclock position with the wheel removed,The other location is on the side of the engine/transmission area not too far to the left ofthe large rubber sideplug.... there is a hose just below it according to the picture. Could this be the small item with the rubber cap that favors a grease fitting???? I don't know .... but will check it out tomorrow.Bordercollie</p>

Thanks BC............Yes, I need to break down and buy the manual......But golly, then I wouldnt get to share with folks on here.......Anyway, thanks....I guess when I do the maintenance next week I will follow lines from the master cylinder and see..........</p>


The question still remains.........do I HAVE to do this........yes, I know maintenance is a must do item and not to be ignored; but is the system so fragile, like in motorcycles, that it really needs this attention.......I guess I am thinking of my ol 54 VW that just keeps on braking with 50 year old brake fluid intact.............Dennis</p>

Hey again! I just checked out the pictures in the parts manual as well after looking at my machine and the front bleeders are indeed on the top of the axle and are protected by a guard device that has a"cap"with a small bolt onit.The rear bleeders are there near that large plug and resemble a grease fitting but with a rubber cap. I agree half of the fun on a forum is the communication between all of us and the sharing info.It took me over 3 yrs to decide on buying the manuals..... but then I do have over 2100 hrs on mine. I will always be glad to share info if I can find it. I'm not saying you need to buy one at all. Just pictures are helpful to me especially when putting things back together.. Ha ha. Yes, I have been in that situation more than once. On the pups.. We have 2.. Millie and Belle.. My sister and I went to Kentucky to pick them up as pups. We got lost late at night in the wrong part of FtCampbell..Finally got back on the interstate,found a safe room , next morning got the pups and headed home... It's a funny story in there about us getting lost and what we saw???but anyway we still laugh about that.Our pups have never been professionally trained but Millie is especially good with the cows. She is obsessed with the 4whr.Belle tries to herd cowsbut she isn't observant. just looks one way... But she loves the RTV and will ride to the end of the earth and wait on the RTV for me there. Rattle the keys or pick up the pliers and she is ready to go. They sleep in the house and love the A/C after working all day.Bordercollie</p>

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Some Tips I have found useful, empty the master cyl. and replace with fresh brake fluid before you start. That shortens the drain time. Second, Start at thefarthestwheel cyl. which shortens the time to drain and buy a brake fluid vacuum. It will pull the fluid thru the system at the wheel cyl. and let you do the job by yourself. Changing the fluid removes the moisture that builds up in the system. KKubota may have some parts in brake system that moisture will be bad for.</p>


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bordercollie said:

; I just checked out the pictures in the parts manual as well after looking at my machine and the front bleeders are indeed on the top of the axle and are protected by a guard device that has a"cap"with a small bolt on it..Bordercollie</p>

Click to expand...

Thanks BC. I thought that might be where Kubota was hiding the front bleed nipple.

Most auto manufacturers recommend replacing your brake fluid every 2 years because brake fluid is hygroscopic (picks up water) and will cause rust in the master and slave cylinder bores. The newer style master cylinder caps with the bellows inside allow the fluid level to drop without allowing air (and hence moisture) to be introduced to the system. A big improvement over the pin-hole baffles in the old style caps.

BTW, my vintage race car gets a brake bleed before EVERY event!

Welcome to the forum Minimack! Glad you found us. bordercollie

If i can add my two cents. You can mix Dot 3 and 4 fluid. Flushing the system is something that needs to be done if you want to keep things operating correctly. If there is anything other than clear fluid at the master cylinder suck it out pour in new fluid and start bleeding. Harley uses Dot 5 fluid which you do not mix with anything but Dot 5. There is a Dot 5. something that can be used with Dot 3 and 4, it is a synthetic fluid but i stick with regular 3 or 4.

Have never changed my brake fluid and my machine is 8 years old.I just look at the fluid and it looks fine and have no problems so why fix it if it aint broke.

I have not changed my brake fluid. For that matters, I don't think I've used my "brake pedal" three times since new.

But changing fluid might be a good idea. Mine looks new.

Our RTV would be just as good using a wooden brake set-up !!!!

Kubota is pretty specific about using DOT 3 brake fluid. I figure their engineers know way more about this stuff than I do. You can't look at brake fluid and tell if it has absorbed moisture, so appearance really doesn't help. It is the water dissolved in the brake fluid that causes all the problems. Much easier and cheaper to change out the brake fluid every 2 years than to replace the master cylinder. Water dissolved in the brake fluid also lowers the boiling point but that is not an issue in a RTV900, only in a race car.

DOT 5 is silicone brake fluid which has its own pros and cons. Mostly it is for vintage or show cars that don't get used frequently and don't really need to stop all that much.

All and probably more than you wanted to know about brake fluid http://en.wikipedia.org/wiki/Brake_fluid

It is replacement of the corrosion inhibitors that make periodically replacing the brake fluid a good idea. The low speeds and minimal use of brakes as a result of the engine braking on the RTV 900 make DOT 3 perfectly adequate for this application.

Good info minimack, Thanks!

What ever you do do not get any synthetic Fluid mixed in. I think Dot 5 is synthetic.
They say that vechiles that have anti lock brakes ( all vechiles now days ) if synthetic fluid was added it will screw up the anti lock system.

The brake system can be gravity bled on these. Start with the farthest cylinder and work forward.

Hey folks! I just had a brake issue I thought might be useful to report. Again, I just bought this RTV used a couple of months ago. I noticed when I bought it that the brake pedal was soft so I figured I would need to bleed the brakes soon. Well, yesterday, I noticed that I had no brake at all. The pedal went all the way to the floor! So, discovered that the fluid level was way down. That tells me why the pedal was soft -- fluid level had leaked down in the past and previous owner just added more fluid after air got in the system.

I filled 'er back up and pumped on the pedal a long time before it pumped up. I parked on a clean concrete surface. I pumped a while and then checked underneath. I found that I had a leak at the right rear cylinder that I could actually hear squirting as I pumped. I had all sorts of fears of having to replace that cylinder at a cost of $235. But I figured I'd make sure all the connections were tight first. Lo and behold, the line connecting to the cylinder was about a half turn loose. I figure that a stick or something hit the fitting and the way it's made, anything that hits either the hose or the metal part at the connection can exert a loosening turning moment on the fitting. Note that this would be true only on the right side. On the left side something hitting the hose or fitting would tend to tighten it. I tightened it up snug, pumped the pedal a lot and found no runs, no drips. Yea!!! I didn't have to buy anything.