Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: kevo0000 on January 29, 2021, 12:24:17 pm
Title: Changing my electric pump on my brake booster
Post by: kevo0000 on January 29, 2021, 12:24:17 pm
Hya all, today I decided to change my electric pump that bolts to the bottom of my hydraulic brake booster, seemed straight forward enough, however I wish I looked at the manual first,
The problem I have encountered was i went underneath this morning, had the new pump with new seals all ready to do a straight swap old for new, firstly I undone the rear bracket bolt, then there were just two bolts connecting it to the booster, I wasn't sure how mutch hydraulic fluid would leak out, so got the new pump all ready with the seals in place,
Anyway undid the two bolts and removed the pump, hardly any fluid loss just a slight drip, so gave it a quick clean with a rag and up with the new pump and two bolts on and tight, less than 5 mins, Then I suddenly noticed a spring and a valve on the floor, well actually I had some carpet laid out to lie on so I didn't hear it drop, we'll I've looked at the manual, and it turns out that it is a relief valve stem and spring and I've worked out from the manual which hole it goes up into, now the spring is slightly narrower at one end and the valve stem seems to fit perfectly into the narrow end of the spring, now this is what I'm not sure about the relief valve stem an fit in the spring 1 way and also the opposite way but it is slightly different on one end,
Now the picture in the manual of this valve stem is not very clear, I've put a magnifying glass on it but still can't work out which way it goes, so il upload some photos and maybe someone has changed one in the past and would know which way it goes, thanks kev
Title: Re: Changing my electric pump on my brake booster
Post by: John Haygarth on January 29, 2021, 01:41:44 pm
Kev, in the 2nd picture there shows some rust or? On the shaft of piston so my thought is to look at the face of the shoulder on that end and see if you can make out any marks that would show the spring seating against it. If there is some marking then it may be the spring locating that face/end to answer your problem. JohnH
Title: Re: Changing my electric pump on my brake booster
Post by: kevo0000 on January 29, 2021, 02:19:21 pm
Kev, in the 2nd picture there shows some rust or? On the shaft of piston so my thought is to look at the face of the shoulder on that end and see if you can make out any marks that would show the spring seating against it. If there is some marking then it may be the spring locating that face/end to answer your problem. JohnH
Ah that's a good idea! Never thought of that il check that out in the morning as its as it was when I took it out, I would be inclined to think that is the end that sits in top of spring, and it seems to fit perfect in the narrow end of spring too, I've put the piston in the other end of spring which is wider and it don't seem right, it's a shame that the workshop manual is not clear, the fact that the old pump hasn't been used for years maybe never used at all, cause its only done just over 100,000 miles since new, so am thinking to myself that the bit with rust on would make sense going into spring as in that picture 2 and the bit thats clean would be on top because it would have oil on it all the time, that's just my theory, could be wrong though, I'm gonna take another very close photo of the diagram in the manual again, zoom on it before I take the photo, then once I've took the photo Il zoom the photo as well and maybe il just see something, or maybe there is someone on the forum that has done this job that hasn't read this post yet, it's not a major problem as if all else fails, il fit as in picture 2 and if it works then that's it, if it doesn't il take it off and turn the piston and try it the other way, at least I know from the diagram which hole it goes into and the piston goes in first then the spring then the pump
Title: Re: Changing my electric pump on my brake booster
Post by: kevo0000 on January 29, 2021, 02:54:26 pm
Ah that's a good idea! Never thought of that il check that out in the morning as its as it was when I took it out, I would be inclined to think that is the end that sits in top of spring, and it seems to fit perfect in the narrow end of spring too, I've put the piston in the other end of spring which is wider and it don't seem right, it's a shame that the workshop manual is not clear, the fact that the old pump hasn't been used for years maybe never used at all, cause its only done just over 100,000 miles since new, so am thinking to myself that the bit with rust on would make sense going into spring as in that picture 2 and the bit thats clean would be on top because it would have oil on it all the time, that's just my theory, could be wrong though, I'm gonna take another very close photo of the diagram in the manual again, zoom on it before I take the photo, then once I've took the photo Il zoom the photo as well and maybe il just see something, or maybe there is someone on the forum that has done this job that hasn't read this post yet, it's not a major problem as if all else fails, il fit as in picture 2 and if it works then that's it, if it doesn't il take it off and turn the piston and try it the other way, at least I know from the diagram which hole it goes into and the piston goes in first then the spring then the pump
Hya John, just found the article in the manual of how to install the pump, and it states that to put the relief valve in slotted end first, then the small end of spring next, then the pump body, so panic over, so if I didn't find it in the manual, then what you said about picture 2 would have been correct anyway, and that's the way I would have tried first, so next job will be that, bad weather tomorrow so may have to wait couple of days, thanks for your help kev