Briggs & Stratton Oil Seals
Genuine Briggs & Stratton oil seals prevent crankshaft and valve stem oil leakage in lawn mower engines and garden equipment. We hold oil seals in stock for PTO side, magneto side, and valve applications worldwide. Crankshaft seals prevent oil escaping around rotating shafts whilst valve stem seals stop oil entering combustion chambers. Common failure causes include worn crankshaft surfaces, excessive crankcase pressure from blown head gaskets, and age-related hardening. Proper installation requires clean surfaces, straight alignment, and checking for shaft grooves. We sell and ship Briggs & Stratton oil seals globally for all engine configurations.
Available Briggs & Stratton Oil Seals
Oil Seal
805049S
Briggs & Stratton
£15.25
In Stock
Oil Seal
795387
Briggs & Stratton
£7.10
In Stock
Oil Seal
391483S
Briggs & Stratton
£4.00
In Stock
Oil Seal
399781S
Briggs & Stratton
£7.00
In Stock
Oil Seal
391086S
Briggs & Stratton
£4.55
Available
Oil Seal
291675S
Briggs & Stratton
£5.00
Available
Oil Seal
691952
Briggs & Stratton
£8.60
Available
Oil Seal
692550
Briggs & Stratton
£7.20
Available
Seal O Ring
710072
Briggs & Stratton
£6.20
View More
Retainer Seal
697478
Briggs & Stratton
£4.05
In Stock
Seal Valve
794086
Briggs & Stratton
£7.30
In Stock
Seal O Ring
270344S
Briggs & Stratton
£4.50
In Stock
Frequently Asked Questions
How do I identify which oil seal is leaking on my engine?
Crankshaft PTO seals leak at the bottom where drive belts attach, causing oil to contaminate belts and puddle beneath the mower. Magneto-side seals leak near the flywheel on top of the engine. Valve stem seals cause blue smoke from the exhaust and oil fouling spark plugs. Clean the engine thoroughly, run it briefly, then inspect for fresh oil trails. Oil around the crankshaft area with dirt buildup indicates seal failure.
Why does my new oil seal keep leaking after replacement?
Worn crankshaft surfaces create grooves that prevent proper sealing even with new seals. Inspect the shaft for scoring, nicks, or wear grooves—polish minor imperfections or fit a repair sleeve over damaged areas. Excessive crankcase pressure from blown head gaskets forces oil past seals. Check breather operation and head gasket condition. Ensure seals install straight without cocking, and the lip faces inward toward engine oil.
Can I replace a crankshaft seal without removing the engine?
PTO-side bottom seals often replace without engine removal on vertical shaft engines if you have adequate access underneath. Remove the drive pulley, extract the old seal using self-tapping screws as pullers, then carefully tap the new seal into place using a socket matching the seal's outer diameter. Magneto-side seals typically require more disassembly. Ensure surfaces are spotlessly clean and check shaft condition before installing replacement seals.
What causes premature oil seal failure on Briggs & Stratton engines?
Blown head gaskets pressurize the crankcase, forcing oil past seals prematurely. Excessive belt tension or faulty electric clutches create side loads that wear crankshaft bearings, causing shaft misalignment. Installing seals crooked or driving them in unevenly damages seal lips. Using aftermarket seals with incorrect materials accelerates failure. Age hardens rubber seal lips, creating leak paths. Clean cooling fins regularly to prevent overheating which degrades seal materials.
Should I use sealant when installing crankshaft oil seals?
Light oil or assembly lube on the seal lip aids installation and prevents tearing, but never use RTV or gasket sealant on the sealing lip itself. Some OEM seals have factory-applied orange or green coatings on the outer diameter for sealing in the bore—if absent, apply minimal RTV to the outer edge only. Use a plastic shim or soda bottle sleeve around the shaft during installation to protect seal lips from damage. Tap seals in evenly using proper-sized drivers.