cerick305 Posted March 27, 2016 Report Posted March 27, 2016 I've noticed my brake pedal seems to be soft initially then the second press its normal pressure. I figured I had air in the lines. I bleed the lines starting on passenger rear, driver rear, passenger front, and finally driver front. Took it for a drive, and same thing. Initial press it is softer than the second. So I figured I didn't bleed the lines good enough. So I did it again with same results. I don't have any lines leaking and master cylinder seems leak free. Now when I say the initial press is soft, the vehicle still breaks fine. But there is a definite hard pedal feel on the second press. Then after a few moments (10 seconds or so) without pressing pedal then the pedal goes back to its softer press. Anyone have any ideas? What I did was open the brake blender valve after hooking plastic hose up to it pitch upward to trap brake fluid on valve and air would rise up. Then pressed brake pedal 4-5 times. Looked and hose had filled with brake fluid and then I tightened bleeder valve. Then checked and refilled master cylinder. I did this process over for the other three brakes. Quote
Young Ed Posted March 27, 2016 Report Posted March 27, 2016 have you checked your shoe adjustments? Quote
P15-D24 Posted March 27, 2016 Report Posted March 27, 2016 You have air in the lines. You may have leak. Did your try pressure bleeding the lines? Quote
cerick305 Posted March 27, 2016 Author Report Posted March 27, 2016 I bleed the lines as described. Quote
cerick305 Posted March 27, 2016 Author Report Posted March 27, 2016 I did not check the show adjustment. But what would that have to do with the initial pedal press to be soft then the second pedal press to be harder? Quote
Young Ed Posted March 27, 2016 Report Posted March 27, 2016 I did not check the show adjustment. But what would that have to do with the initial pedal press to be soft then the second pedal press to be harder? Too much space between shoes and drum to get a good pedal the first time? Can't really explain it but I had that on my pickup and I adjusted the shoes and it went away. 1 Quote
mopar_earl Posted March 27, 2016 Report Posted March 27, 2016 Adjustment and/or travel issue. Air is spongy, pump up is adjustment/travel. Lots will tell you air but just isn't so. Make sure your master cylinder rod adjustment is correct and than your brake adjustments. Earl Quote
soth122003 Posted March 27, 2016 Report Posted March 27, 2016 (edited) Hey Cerick, I/ve got the same deal on my brakes. Chances are your back brake shoes are not adjusted right. The bottom line is your shoes, when adjusted properly, are only about 1/16 of an inch from the drum. If any shoe is more than that, it takes more fluid to move the piston on the wheel cylinder further out to take up the space between the shoe and the drum. Your Master cylinder only moves so much fluid per push of the brake pedal. When the brakes are adjusted right it will only take about 1/4 to 1/3 of pedal to have firm brakes. The reason after 10 seconds or so you have to pump again is because the brake shoe return springs pull the shoe back to the full retract position. The fronts on my P-15, I can dial right in. The back brakes need the AMCO tool to do it right. The fronts can be adjusted easily because taking the drum off is easy and you can adjust the major and minor with very little trouble, but the back needs a puller to remove the drum and then you adjust the major adjustment and re-install the drum then adjust the minor adjustment. Because the cars only had the single master cylinder, the pressure will only be firm on the first pump when all shoes are in adjustment. My back shoes are out just enough to require 2 pumps for a firm high pedal. So I drive really conservative. I would anyway so some clown doesn't plow into me or me into them from them not paying attention. Joe Edited March 27, 2016 by soth122003 Quote
_shel_ny Posted March 27, 2016 Report Posted March 27, 2016 Proper clearance for brake shoes is .006. Minor adjustment is needed as more miles are put on the vehicle. Quote
Don Coatney Posted March 27, 2016 Report Posted March 27, 2016 Did you bleed all 6 wheel cylinders? 4 in front, 2 on the rears. Quote
cerick305 Posted March 27, 2016 Author Report Posted March 27, 2016 4 up front? I'll do it again...... Quote
P15-D24 Posted March 27, 2016 Report Posted March 27, 2016 And start with the furthest from the master and work back to the closest to the master. 1 Quote
_shel_ny Posted March 27, 2016 Report Posted March 27, 2016 4 up front? I'll do it again...... ... 1 Quote
soth122003 Posted March 27, 2016 Report Posted March 27, 2016 Thanks Shel, I knew it had a 6 in the measurement. I just had fractions on the brain. Joe Quote
desoto1939 Posted March 27, 2016 Report Posted March 27, 2016 I have the ammco brake tool that is used to adjust the shoes properly to the drum. Contact me. Rich Hartung Desoto1939@aol.com Quote
cerick305 Posted March 28, 2016 Author Report Posted March 28, 2016 I was about to re-bleed the lines and noticed a small crack in one of the hoses. I took the hose into Napa and autozone looking for a replacement. However, I could not find one. Anyone have any ideas? I think the female end is 3/8" NPT and hthr male end is 'possibly' 7/16". see picture.... Quote
Dodgeb4ya Posted March 28, 2016 Report Posted March 28, 2016 Rock Auto has both front and rear. hoses... That's where I buy old Mopar brake parts from now days as they have great cataloging and prices plus fast shipping....http://www.rockauto.com/en/catalog/plymouth,1947,p15+deluxe,3.6l+218cid+l6,1486706,brake/wheel+hub,hydraulic+hose,1792 Quote
Plymouthy Adams Posted March 28, 2016 Report Posted March 28, 2016 Many times I will use the Rock auto site to get a number to cross over to a part at FLAPS..can help you get the part in your hand a bit quicker. If not in a hurry, Rock is good, have used them before with good results. Quote
desoto1939 Posted March 28, 2016 Report Posted March 28, 2016 OK here comes the Brake catalogs again to the rescue. Getting and having the various catalogs in your literature is important. As per my EIS brake catalog: P)lymouth p15 1946-48 Brake Hoses front SP967 rear SP790 This would be a TYpe 2 hose 7/16" by 20 threads and the other end is 3/8" by 24 threads SP967 is a total of 11 1/8 inches SP790 is 16 27/32 inches I have other major information on brakes on my catalogs that I have scanned and this should be in you collection of information. Contact me for the information. Rich Hartung Desoto1939@aol.com Quote
cerick305 Posted March 28, 2016 Author Report Posted March 28, 2016 Just ordered from rockauto. That's a lot all for your help!! Quote
Bingster Posted March 28, 2016 Report Posted March 28, 2016 I bought front hoses from AB a few years ago. Would rock auto have the same hoses or a better quality? I only want to do this once. Quote
Dodgeb4ya Posted March 28, 2016 Report Posted March 28, 2016 He might just buy them from RA and re sell them to you! RA sometimes has some really good deals on Raybestos brake parts. I get twice a year huge discounts on discontinued parts. Last 2 deals were flathead new "Gates" water pumps and raybestos full set (6) of wheel cylinders @ $100.00...USA stamped too. Quote
cerick305 Posted March 30, 2016 Author Report Posted March 30, 2016 Do I use any thread sealant on the brake line? Quote
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