Sean Posted October 6, 2011 Share Posted October 6, 2011 Bleeding: Power bleeders are a bother, especially since you have to use more fresh fluid... How so? Link to comment Share on other sites More sharing options...
danilo Posted October 7, 2011 Share Posted October 7, 2011 Beginners :-) Buy a n inexpensive Disposable Plastic Syringe (Horse supply store $2) Fill it with fresh fluid attach it to the bleeder nipple of a Brake caliper using a suitible bit of tubing. Open the bleeder and Force inject the contents of the Syringe.. slowly. Do the other bleeders around the car sequentially. Job Done. Link to comment Share on other sites More sharing options...
JohnK Posted October 7, 2011 Share Posted October 7, 2011 How so? A power/pressure bleeder not only creates pressure at the master cylinder reservoir, it also adds fluid to the reservoir to prevent the reservoir running dry and air being pushed through the system. As a result the bleeder needs a supply of fresh brake fluid that's sufficient to avoid running dry - erring on the side of caution, this usually involves adding a considerable excess of what could be done by the slower, step-at-a-time vacuum procedure. E.g. my favorite add for one of these units usually appears at the back of Automobile magazine with a young honey announcing "I really love a hard brake pedal!" After you/I get past that, notice that what they're selling is a insecticide sprayer refitted for the purpose - so, considering the size of that container, you must have to add at least several pints to the bottom of the thing - and of course pitch any you don't use. The point of this whole thing is due to the property of brake fluid absorbing water over time, which is why your owner's manual says to change (flush out) your brake system with new fluid every two years - otherwise you face a rusty mess as the years go by and have to replace your calipers and fittings, and ... Link to comment Share on other sites More sharing options...
bsimon Posted October 7, 2011 Share Posted October 7, 2011 I second John's take on brake bleeding. Pressure systems make the most sense. When you use a pressure bleeder, there is very little chance to introduce air into the brake system. Vacuum systems have the ability to suck air in through cylinder cups and seals. I liken the vacuum bleeding process to some poorly designed electrical cabinet cooling systems I have to deal with. Crappy systems have fans sucking the air into the cabinet though filter panels. This means dirt and dust can be pulled through the door seals and joints in the conduit. Good designs pressurize the cabinet with filtered air so any leaks are blowing clean air outwards. Same goes for heavy equipment cabs. Link to comment Share on other sites More sharing options...
Sean Posted October 7, 2011 Share Posted October 7, 2011 (edited) A power/pressure bleeder not only creates pressure at the master cylinder reservoir, it also adds fluid to the reservoir to prevent the reservoir running dry and air being pushed through the system. As a result the bleeder needs a supply of fresh brake fluid that's sufficient to avoid running dry - erring on the side of caution, this usually involves adding a considerable excess of what could be done by the slower, step-at-a-time vacuum procedure. E.g. my favorite add for one of these units usually appears at the back of Automobile magazine with a young honey announcing "I really love a hard brake pedal!" After you/I get past that, notice that what they're selling is a insecticide sprayer refitted for the purpose - so, considering the size of that container, you must have to add at least several pints to the bottom of the thing - and of course pitch any you don't use. The point of this whole thing is due to the property of brake fluid absorbing water over time, which is why your owner's manual says to change (flush out) your brake system with new fluid every two years - otherwise you face a rusty mess as the years go by and have to replace your calipers and fittings, and ... Right - of course. But it doesn't have to be done it that way. It is simple enough to just not put fluid into the canister of the power bleeder, but rather top off the MC, pressurize, and bleed a wheel or two until the fluid level in the MC starts to get low (just as would be done with the second person method). Then de-pressurize, top off MC, re-pressurize, and continue. This method of using a power bleeder uses no more fluid than the two-person manual-pump method, and the power bleeder remains clean, as the fluid never comes into contact with any part of it, other than maybe the inside of the reservoir pressure cap. Edited October 7, 2011 by Sean Link to comment Share on other sites More sharing options...
JohnK Posted October 8, 2011 Share Posted October 8, 2011 Sean, I agree, and even with the extra moving about, it shouldn't take any more work than the vacuum method - and you get the benefits of the pressure method. The worst problem I have is finding caps to match my M/C reservoirs: my Se7en has Wilwood remotes and a separate, integral, clutch (it must be the same as the plastic ones, I think); and then there's my Civic. 's never simple is it? Link to comment Share on other sites More sharing options...
Croc Posted October 9, 2011 Author Share Posted October 9, 2011 (edited) Mike, I'm guessing you have the upgraded braided Stainless hoses on your CSR Generally, stainless brake lines are simple extruded Teflon hose encased in stainless braid. If you are seeing black specs and weeping, I would imagine that they are not Teflon but nitrile (Buna-N, NBR) hoses meant for fuel or oil. Nitrile lines are not pressure rated for brakes. Brake fluid eats nitrile as well. Methinks someone speced the wrong materials at Caterham. Scary... And the winner is Bob! All hoses were pulled off the car from master cylinder down to each wheel and tested in the CSI boffin lab. They were of two types: (a) stainless braided hoses at each wheel. (b) some rubbery looking ones at the brake fluid reservoir mounted on the scuttle. The bad hoses were the nonbraided black hoses (3 of them) at the brake fluid reservoir. They were Buna N hoses and clearly wrong spec. They can be seen in this photo running along the foreground of the engine bay up to the reservoir mounted on the scuttle. http://i15.photobucket.com/albums/a354/mjohnson555/seats/CSR/Colorado%20April%202011/DSC_5414_edited-1.jpg The stainless ones were found to be fine but I replaced them out of caution as I was not in a trusting mood. I used Tilton as my source for replacements. The replacements are shown in the following photo: http://i15.photobucket.com/albums/a354/mjohnson555/seats/CSR/October%202011/DSC_1994_edited-1.jpg I lost some paint off the car from where the leaking fluid ate it up but I will take that as a battle scar that could have been much worse. The scary bit of this story is that these hoses may not be an isolated occurrence and may be part of a bad batch in late 2010. It would not be limited to new kits but could also be older cars that sourced replacements during this period. I would encourage anyone with a Caterham seven to give an extra inspection in this area. Edited October 9, 2011 by Croc Link to comment Share on other sites More sharing options...
bsimon Posted October 9, 2011 Share Posted October 9, 2011 Hmm...brake fluid reservoir hoses. A common mistake in VW and Mercedes restorations. (Don't ask me how I know.) It always looks as though a bit of common fuel hosepipe from the auto parts store should work nicely. After all, it's only under atmospheric pressure, right? It's not until later that certain migrating plasticizers create havoc.:ack: Glad to see you've got things sorted. Link to comment Share on other sites More sharing options...
blubarisax Posted October 9, 2011 Share Posted October 9, 2011 Great detective work Mike. My brake reservoir setup looks exactly like your original configuration. Guess I better replace it ASAP. What kind of hose did you use? Bob, yes, the hoses are not under any pressure. Karl Link to comment Share on other sites More sharing options...
Croc Posted October 9, 2011 Author Share Posted October 9, 2011 Its easy, just ring Tilton http://tiltonracing.com/content.php?page=prosmenu and explain what you need - length, diameter, etc and they will spec it for you. I have used them before and found them to be very helpful. Link to comment Share on other sites More sharing options...
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