Has anyone converted to DOT5 brake fluid without installing all new lines? If not, how did you make sure all DOT3 or DOT4 fluid was removed from the lines? I understand 3 or 4 and 5 do not mix and mixing them can be a real problem. I have installed all new wheel cylinders, three new rubber lines and know I need to clean the master cylinder, but am concerned about what may remain in the metal lines. What is the best cleaning solution for getting rid of the DOT3 or 4? Thanks!
Welcome to the forum, Harold. If you're going to go with DOT5, you definitely need to purge your lines as well as the master cylinder and slave cylinders. Here's one way that you can do it. You will need to remove as much of the old brake fluid as possible in the master cylinder. Go buy some rubbing alcohol and fill the m/c with it and proceed to bleed each wheel until it runs clear indicating that all of the old brake fluid has cleared that section of line. Once that has been done, you really need to remove the m/c and slave cylinders and clean them thoroughly with soap and water and make sure that all parts are done that way. Once put back together, you're ready to add your new fluid. Hope this helps. Ken P.S. What part of W. Tenn are you from?
Thanks Ken. I wasn't sure what I needed to used for a cleaner. Since there has never been fluid of any kind in the new rubber lines and new wheel cylinders, I think in order to save having to also soap clean them of anything I'll disconnect the metal line at the four extremities (where they attach to the rubber line and the left rear cylinder) one at a time and bleed with the alcohol. Then it will only be the master cylinder that needs a soap cleaning and maybe blowing out the metal lines as best as possible. My biggest problem may be getting my "petal pumper helper" to stick around long enough. Oh yeah, I'm not "from W. Tennessee," I'm still here, even after seventy years. I'm in Fayette County, east of big Shelby County where Memphis is.
I gotcha! Southwest Tn boy. My roots are in N. West Tenn. Went to high school in Henry Co. and college in Weakley Co. Nice to have another Tennessee lad on the forum! I need to ask though, why do you want to go to Dot5 silicone based brake fluid? If you plan to drive your truck, there is no need to convert IMHO. Just curious.
We pass through Henry county often on camping trips, headed to LBL or beyond. That's the problem, it doesn't get driven very much. When I pulled the wheel cylinders two were frozen up, one looked like it had leaked all the fluid from the master cylinder, which had an empty reservoir and all the rubber was hard. Maybe it'll get driven more, but if not I think the Silicone would be better. I may change my mind. Did I read on here somewhere that DOT4 is preferred over DOT3?
Welcome harold ! If you soap and water wash ANY hydraulic parts , they'll need the Isopropal Alcohol cleaning after , not before . Don't worry about the new cylinders & hoses but *do* take the master apart and clean it out 1000 % , flush the hard lines too then blow them dry with air ~ use a bicycle pump if you need to . Or , just look for DOT 5.5 as that mixes just fine with DOT 3 & 4 . DOT 4 is better because it has a higher boiling point , it is getting harder to find these days though .
Brakes and stuff Hope you don't mind me jumping in with a question on the brakes also. My system is all new and before I add the fluid I need to know if I'm supposed to add a residual valve. I have stock drums all around. I will be upgrading to a dual master cylinder but I"m confused about resudual vavles and proportioning valves. Do I need both? Where do I put them - front line or rear line? I also need to find the brass plug for one side of the original line connector and some other fittings if someone knows a good source. Thanks
Dual Master Cyl. You don't need either if your brakes are in good shape and you have the proper master cylinder...
THanks Nate, saved me some money on the valves, and the brakes are new but what's the PROPER M/C. The one I bought is 1" bore with dual sections. I got the part number from one of the forums a couple of years ago when I started this project so I don't even know anything about it anymore other than it was pretty cheap.
Since You Have It..... I'd say go ahead and mount it up and give it a try , be sure to do some speed testing on an otherwise empty of traffic long open road... There are two commonly used dual MC's for this , 1971 Mustang with drum brakes or similar year Nova , also with drum brakes . Many dual master's have a stepped bore , being designed for one circuit of disc brakes , this sometimes works O.K. with all drums , other times not so much so take your time and ensure it's properly bled out and all four wheels are correctly adjusted cold before deciding to try a different MC . Look through all posts made by Evan , he knows this stuff far better than I .
Craig Evan's handle is " Coilover " and whenever he says one thing and I , a different thing , follow his advice . Both will work yes but he's very attuned to modern methods & ideas , I'm still kinda stuck in the distant past as it works .
