ArdWrknTrk Posted December 17, 2020 Share Posted December 17, 2020 I second that recommendation. I hated the rusty, leaky cast iron master cylinder, but love the plastic/aluminum one. No leaks, I can see how much fluid I have, and I have a home-made cap that allows me to put air pressure on it to bleed the brakes easily. Another thing I did is to put a hydroboost booster on. Runs off the power steering pump and really helps get the brakes to work NOW. Makes the brakes seem very modern. Hydroboost works great and eliminates the massive vacuum can altogether. I imagine this leaves you more space to change plugs 7&8 as well as unwrapping the fuel pump/trailer relays. The later alloy MC plastic reservoir is pretty much a direct swap except front and rear are reversed, and you need that residual pressure check valve for drum brakes in the rear. Be aware they come in different bore sizes with different flange bolt patterns as well. Link to comment Share on other sites More sharing options...
Rembrant Posted December 17, 2020 Share Posted December 17, 2020 Every time I open the hood, my eyes go strait to it. Is this mod done up somewhere on our forum? I like it! I was doing the exact same thing! Even the nice mint expensive trucks for sale on Ebay will have a beautiful engine bay and all you can see is that rusty master cylinder lol. It's a pretty straight forward installation. There are really only two issues: 1. Is that the front and rear brake ports are reversed from the Bullnose master cylinder. I was running all new brake lines at the time, so it was a non-issue for me. However, I did see a guy on Facebook a month or two ago do the swap with a used master, and all he did was grab the two brake lines and bend them around each other to fit the new master. 2. The later master cylinder requires a residual pressure valve for the rear brakes, and it is NOT included with the purchase of a new master cylinder. They are readily available at the junkyard though, so I grabbed a couple of them...one to install, and another for a spare. I'm pointing at it in the picture below: It bolts right up to the Bullnose brake booster no problem. I did have to adjust the booster pushrod a little bit, but I think that's a given anyway. I did away with the prop valve on the frame...the later trucks didn't have them anyway. I took the wires that used to connect to it and connected them to the float switch on the later master, so my low-brake-fluid warning light in the dash still works. If you go to the junkyard to get a residual pressure valve (or the whole master itself) also grab the plug and wiring for the float switch. A former member on here put me on to this and I'm glad he did as I was re-doing the whole braking system anyway. Otherwise, I think Scott's powder coating method noted above is also an great idea. Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 17, 2020 Share Posted December 17, 2020 Every time I open the hood, my eyes go strait to it. Is this mod done up somewhere on our forum? I like it! I was doing the exact same thing! Even the nice mint expensive trucks for sale on Ebay will have a beautiful engine bay and all you can see is that rusty master cylinder lol. It's a pretty straight forward installation. There are really only two issues: 1. Is that the front and rear brake ports are reversed from the Bullnose master cylinder. I was running all new brake lines at the time, so it was a non-issue for me. However, I did see a guy on Facebook a month or two ago do the swap with a used master, and all he did was grab the two brake lines and bend them around each other to fit the new master. 2. The later master cylinder requires a residual pressure valve for the rear brakes, and it is NOT included with the purchase of a new master cylinder. They are readily available at the junkyard though, so I grabbed a couple of them...one to install, and another for a spare. I'm pointing at it in the picture below: It bolts right up to the Bullnose brake booster no problem. I did have to adjust the booster pushrod a little bit, but I think that's a given anyway. I did away with the prop valve on the frame...the later trucks didn't have them anyway. I took the wires that used to connect to it and connected them to the float switch on the later master, so my low-brake-fluid warning light in the dash still works. If you go to the junkyard to get a residual pressure valve (or the whole master itself) also grab the plug and wiring for the float switch. A former member on here put me on to this and I'm glad he did as I was re-doing the whole braking system anyway. Otherwise, I think Scott's powder coating method noted above is also an great idea. There is another way on the reversed lines. As said, I used a '95 F450 master but used the master-to-proportioning valve lines from a '90 F250. The '90 had the later master so had the lines reversed, and they still had the proportioning valve on the frame. It all bolted up like it was meant to be there and I didn't have to have the residual pressure valve. Link to comment Share on other sites More sharing options...
Machspeed Posted December 17, 2020 Share Posted December 17, 2020 Every time I open the hood, my eyes go strait to it. Is this mod done up somewhere on our forum? I like it! I was doing the exact same thing! Even the nice mint expensive trucks for sale on Ebay will have a beautiful engine bay and all you can see is that rusty master cylinder lol. It's a pretty straight forward installation. There are really only two issues: 1. Is that the front and rear brake ports are reversed from the Bullnose master cylinder. I was running all new brake lines at the time, so it was a non-issue for me. However, I did see a guy on Facebook a month or two ago do the swap with a used master, and all he did was grab the two brake lines and bend them around each other to fit the new master. 2. The later master cylinder requires a residual pressure valve for the rear brakes, and it is NOT included with the purchase of a new master cylinder. They are readily available at the junkyard though, so I grabbed a couple of them...one to install, and another for a spare. I'm pointing at it in the picture below: It bolts right up to the Bullnose brake booster no problem. I did have to adjust the booster pushrod a little bit, but I think that's a given anyway. I did away with the prop valve on the frame...the later trucks didn't have them anyway. I took the wires that used to connect to it and connected them to the float switch on the later master, so my low-brake-fluid warning light in the dash still works. If you go to the junkyard to get a residual pressure valve (or the whole master itself) also grab the plug and wiring for the float switch. A former member on here put me on to this and I'm glad he did as I was re-doing the whole braking system anyway. Otherwise, I think Scott's powder coating method noted above is also an great idea. Thanks for posting that up, Corey! I like the master cylinder change on your truck and I may eventually go that route. I have the Eastwood stuff for which I was going to use on my Mustang master cylinder so I may just go that route for now. When I pull my booster, I'll spray it with some black SPI epoxy which is unaffected by brake fluid. I paint everything with that epoxy. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted December 17, 2020 Share Posted December 17, 2020 There is another way on the reversed lines. As said, I used a '95 F450 master but used the master-to-proportioning valve lines from a '90 F250. The '90 had the later master so had the lines reversed, and they still had the proportioning valve on the frame. It all bolted up like it was meant to be there and I didn't have to have the residual pressure valve. Gary, can you post what Big Blue looks like from the same perspective? (hood latch, I presume) That might show how compact Hydroboost is compared to a vacuum booster. Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 17, 2020 Share Posted December 17, 2020 Gary, can you post what Big Blue looks like from the same perspective? (hood latch, I presume) That might show how compact Hydroboost is compared to a vacuum booster. Jim - What booster? I cropped it to match Cory's shot, using the windshield wiper motors and the DS-II modules as the references. Note where the clutch master cylinder is and how close the vacuum booster comes to it in his pic. Link to comment Share on other sites More sharing options...
Matt Wood Posted December 17, 2020 Author Share Posted December 17, 2020 Jim - What booster? I cropped it to match Cory's shot, using the windshield wiper motors and the DS-II modules as the references. Note where the clutch master cylinder is and how close the vacuum booster comes to it in his pic. Thanks everyone for all the brilliant methods! Gary i think i want to go down your route as it just seems like the best way to bring the brakes out of the past Do you have a write up on what you did exactly? or any modifications you needed to do? I still have the standard PS pump as i seem to have been lucky and its quiet as a mouse lol. Am i still able to use the hydroboost system? How exactly does the hydro system work? Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 17, 2020 Share Posted December 17, 2020 Thanks everyone for all the brilliant methods! Gary i think i want to go down your route as it just seems like the best way to bring the brakes out of the past Do you have a write up on what you did exactly? or any modifications you needed to do? I still have the standard PS pump as i seem to have been lucky and its quiet as a mouse lol. Am i still able to use the hydroboost system? How exactly does the hydro system work? Matt - The best writeup is on the page at Documentation/Driveline/Brakes and go to the Master Cyl's & Boosters tab and then the Hydroboost Upgrade tab. The instructions there are from Hydratech, and they sell kits for upgrading trucks. And yes, you can use your C-II pump. The pump supplies the pressure to the hydroboost system, which has two outlets - one is pressure to the power steering box and the other is the return. The return from the power steering box goes to the cooler on the frame and then the two returns, the power steering and the hydroboost, merge and go back into the pump. Need a diagram? Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted December 17, 2020 Share Posted December 17, 2020 Jim - What booster? I cropped it to match Cory's shot, using the windshield wiper motors and the DS-II modules as the references. Note where the clutch master cylinder is and how close the vacuum booster comes to it in his pic. But note that you need to move the pivot pin on the brake pedal, and need the correct bore to have the right ratio for the smaller brakes found on 150's. If you swap a 450 master into a 150 the ratio is going to be way off. This is why I've used the setup from an Astrovan in the 150's. Link to comment Share on other sites More sharing options...
Matt Wood Posted December 17, 2020 Author Share Posted December 17, 2020 Matt - The best writeup is on the page at Documentation/Driveline/Brakes and go to the Master Cyl's & Boosters tab and then the Hydroboost Upgrade tab. The instructions there are from Hydratech, and they sell kits for upgrading trucks. And yes, you can use your C-II pump. The pump supplies the pressure to the hydroboost system, which has two outlets - one is pressure to the power steering box and the other is the return. The return from the power steering box goes to the cooler on the frame and then the two returns, the power steering and the hydroboost, merge and go back into the pump. Need a diagram? I think i got the idea, here is what i got from your description... I appologise in advance for how poor this drawing is lol, its hard to draw with a mouse haha Does this seem about right? By cooler do you mean the ally hard line that curls round the cross member? Link to comment Share on other sites More sharing options...
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